Relevant bibliographies by topics / Ferrites spinels / Journal articles

To see the other types of publications on this topic, follow the link: Ferrites spinels.

Journal articles on the topic 'Ferrites spinels'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Ferrites spinels.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

de la Torre, Ernesto, Ana Lozada, Maricarmen Adatty, and Sebastián Gámez. "Activated Carbon-Spinels Composites for Waste Water Treatment." Metals 8, no. 12 (2018): 1070. http://dx.doi.org/10.3390/met8121070.

Full text

Abstract:

Nowadays, mining effluents have several contaminants that produce great damage to the environment, cyanide chief among them. Ferrites synthesized from transition metals have oxidative properties that can be used for cyanide oxidation due to their low solubility. In this study, cobalt and copper ferrites were synthesized via the precipitation method, using cobalt nitrate, copper nitrate, and iron nitrate as precursors in a molar ratio of Co or Cu:Fe = 1:2 and NaOH as the precipitating agent. The synthesized ferrites were impregnated in specific areas on active carbon. These composites were characterized using X-Ray Diffraction (XRD) and Scanning Electron Spectroscopy (SEM). The XRD results revealed a cubic spinel structure of ferrites with a single phase of cobalt ferrite and two phases (copper ferrite and copper oxides) for copper. The CoFe2O4 impregnated on active carbon reached a cyanide oxidation of 98% after 8 h of agitation; the composite could be recycled five times with an 18% decrease in the catalytic activity. In cobalt ferrites, a greater dissolution of iron than cobalt was obtained. In the case of copper ferrite, however, the copper dissolution was higher. These results confirm that ferrites and activated carbon composites are a novel alternative for cyanide treatment in mining effluents.

APA, Harvard, Vancouver, ISO, and other styles

Ajeesha, T. L., Ashwini Anantharaman, Jeena N. Baby, and Mary George. "Structural, Magnetic, Electrical and Photo-Fenton Properties of Copper Substituted Strontium M-Hexagonal Ferrite Nanomaterials via Chemical Coprecipitation Approach." Journal of Nanoscience and Nanotechnology 20, no. 3 (2020): 1589–604. http://dx.doi.org/10.1166/jnn.2020.17132.

Full text

Abstract:

Copper substituted strontium ferrite nano spinels were synthesized by facile chemical coprecipitation method. Structural properties of all the nano materials were examined using Powder X-ray Diffraction of size ranging 22–50 nm and High Resolution Transmission Electron Microscopy which further revealed the formation of hexagonal spinel structure. The analysis of FT-IR spectra of all the samples confirmed the formation of M–O bond with spinel structure having characteristic peaks at 422 cm-1 and 586 cm-1. All the samples were subjected to dielectric studies at room temperature. A quite narrow band gap around 1.5–1.6 eV for all the samples indicates that these ferrites can behave as visible light photocatalysts. The as synthesized nano spinels were proposed to be promising heterogeneous Photo-Fenton catalysts under visible light for the degradation of organic pollutants. The photo catalytic degradation results revealed 94% degradation for all the prepared nano catalysts. The materials displayed remarkable photo-stability with recyclability up to five consecutive cycles. VSM studies of the materials exhibited weak ferromagnetic property with high surface area. Therefore, these magnetic materials presented no significant loss in activity specifying an exceptional capacity of ferrites to remove organic pollutants from wastewater.

APA, Harvard, Vancouver, ISO, and other styles

Maklad, M. H., N. M. Shash, and H. K. Abdelsalam. "Synthesis, characterization and magnetic properties of nanocrystalline Ni1-xZnxFe2O4 spinels via coprecipitation precursor." International Journal of Modern Physics B 28, no. 25 (2014): 1450165. http://dx.doi.org/10.1142/s0217979214501653.

Full text

Abstract:

Nanocrystalline Ni 1-x Zn x Fe 2 O 4 (0.0 ≤ x ≤ 1.0) spinels are synthesized with a crystallite size range 5–2.2 nm, using different annealing temperatures. The influence of zinc content as well as grain size of ferrite on the ferrite microstructure, therefore on the physical properties of ferrite, are investigated by means of X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), thermal analysis (TG, DTG, DSC) and infrared microscopy (IR). XRD results confirm single phase spinel structure for ferrite with Zn content x = 0.1 whereas second phase appears in higher zinc content ferrites. Thermal analysis shows an endothermic peak at ~ 720°C–750°C reveals the removal of defective surface layer existed on the surface of ferrite grains, which leads to cation redistribution. This is supported by the shift observed in IR bands as a result of the increase in zinc content or calcination temperature. Ferrite with composition Ni 0.7 Zn 0.3 Fe 2 O 4 calcined at 1000°C has the maximum saturation magnetization Ms among various compositions at different calcination temperatures. The Ms and the coercivity Hc of the ferrites nanoparticles are different from their corresponding bulk, which attributes to a defective surface layer, controlling the ultrafine particle behavior.

APA, Harvard, Vancouver, ISO, and other styles

Ranganath, Kalluri V. S., Mahendra Sahu, Melad Shaikh, et al. "CoFe2O4-decorated carbon nanotubes for the dehydration of glucose and fructose." New Journal of Chemistry 40, no. 5 (2016): 4468–71. http://dx.doi.org/10.1039/c6nj00501b.

Full text

Abstract:

Carbon nanotubes were decorated with various ferrites of normal and inverse spinels and were characterized using XRD, Raman, SEM and TEM analysis. The inverse-spinel-decorated CNTs were successfully evaluated in the dehydration of glucose and fructose.

APA, Harvard, Vancouver, ISO, and other styles

Abd El-Salaam, Khalf-Alla M., Abd El-Aziz A. Said, Ahmed M. El-Awad, Ehsan A. Hassan, and Mohamed M. M. Abd El-Wahab. "Structure and Electronic Effects of Cobalt Ferrites, CoxFe3-xO4, on Catalytic Decomposition of Isopropyl Alcohol." Collection of Czechoslovak Chemical Communications 59, no. 9 (1994): 1939–50. http://dx.doi.org/10.1135/cccc19941939.

Full text

Abstract:

The cobalt ferrite spinel oxides CoxFe3-xO4 (O < x < 3) have been prepared by coprecipitation. Their structures were characterized by DTA, X-ray diffraction and IR spectra, and their surface properties were determined from nitrogen adsorption isotherms at -196 °C. Conductance of all the compositions was studied with and without isopropanol. The variation of Eσ values was discussed in terms of oxide semiconducting properties and of ion distribution in the octahedral-tetrahedral sites of the spinel structures. The catalytic decomposition of isopropanol at 325 °C in a flow system allowed to conclude that the inverse spinels formed in the iron-rich region are active and selective sites for acetone formation, in contrast to the inverse spinels formed in the cobalt-rich region. On the other hand, the region of normal spinels showed low activity and selectivity to acetone formation. Correlations between the composition and electronic and catalytic properties of the catalysts are reported.

APA, Harvard, Vancouver, ISO, and other styles

Astik, Nidhi M., and G. J. Baldha. "Investigation of Structural, Electrical and Magnetic Properties of Mixed Ferrite System." Advanced Materials Research 1047 (October 2014): 119–22. http://dx.doi.org/10.4028/www.scientific.net/amr.1047.119.

Full text

Abstract:

The mineral having chemical compositional formula MgAl2O4 is called “spinel”. The ferrites crystallize in spinel structure are known as spinel-ferrites or ferro-spinels. The spinel structure has an fcc cage of oxygen ions and the metallic cations are distributed among tetrahedral (A) and octahedral (B) interstitial voids (sites). A compound of Co0.85Ca0.15-yMgyFe2O4 (y=0.05, 0.10, 0.15) is synthesized in polycrystalline form, using the stoichiometric mixture of oxides with conventional standard ceramic technique and characterized by X-ray diffraction (XRD).The XRD analysis confirmed the presence of cubic structure. The intensity of each Bragg plane is sensitive to the distribution of cations in the interstitial voids of the spinel lattice. The computer program Powder X software for XRD analysis has been utilized for this purpose. The compositions of Co0.85Ca0.15-yMgyFe2O4 (y=0.05, 0.10, 0.15) ferrites have been prepared by standard ceramic method with double sintering at 950°C, 1100°C. In present study, we report the structural, electrical and magnetic properties of above said compound.

APA, Harvard, Vancouver, ISO, and other styles

Mazurenko, Ju. "Nickel substituted effect of on structural, Mössbauer and dielectric properties of spinel-type lithium ferrites." Physics and Chemistry of Solid State 21, no. 3 (2020): 453–61. http://dx.doi.org/10.15330/pcss.21.3.453-461.

Full text

Abstract:

Ni-substituted lithium ferrite Li0.5-x/2NixFe2.5-x/2O4, where (х=0.0, 0.2, 0.4, 0.6, 0.8, 1.0) synthesized through sol-gel auto-combustion method was investigated for its structural, Mossbauer, and dielectric properties. At low doses of substitution, two spinels of the same composition coexist in the structure, one of spatial group P4332, so-called spinel with superstructure, in which the iron and lithium ions are arranged along the crystallographic direction <110> and the other is a spatial group Fd3m, random spinel. The presence of both spinels is observed at low content of the doped element (x = 0.2 and 0.4). In case of increase Ni2+ ions, random component disappears and only the ordered phase remains. The particle sizes of the synthesized product are around 22-45 nm. According to the proposed cationic distribution of Nickel ions are localized in the A-site and lithium ions in the B-site. Iron ions are redistributed over both sites at a ratio of about 1:2. It is shown, that the conductive and dielectric properties of the synthesized powders have a frequency dependence characteristic of ferrite materials, the behavior of which is explained based on the hopping mechanism of conductivity and inter-grain polarization.

APA, Harvard, Vancouver, ISO, and other styles

Antoshina, L. G., A. N. Goryaga, and A. I. Kokorev. "Magnetic anisotropy in ferrites–spinels with frustrated magnetic structure." Journal of Magnetism and Magnetic Materials 258-259 (March 2003): 516–19. http://dx.doi.org/10.1016/s0304-8853(02)01130-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Mounkachi, O., M. Hamedoun, M. Belaiche, et al. "Synthesis and magnetic properties of ferrites spinels MgxCu1−xFe2O4." Physica B: Condensed Matter 407, no. 1 (2012): 27–32. http://dx.doi.org/10.1016/j.physb.2011.09.023.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Diodati, Stefano, Richard I. Walton, Simone Mascotto, and Silvia Gross. "Low-temperature wet chemistry synthetic approaches towards ferrites." Inorganic Chemistry Frontiers 7, no. 18 (2020): 3282–314. http://dx.doi.org/10.1039/d0qi00294a.

Full text

Abstract:

Solution chemistry allows the crystallisation of range of iron oxides, including MFe2O4 spinels, MFeO3 perovskites and hexaferrites, such as BaFe12O19, with nanoscale crystallinity and properties suitable for fields such as catalysis and electronics.

APA, Harvard, Vancouver, ISO, and other styles

Hochu, F., and M. Lenglet. "Co(II) Optical Absorption in Spinels: Infrared and Ligand-Field Spectroscopic Study of the Ionicity of the bond. Magnetic Structure and Co2+→Fe3+MMCT in Ferrites. Correlation with the Magneto-Optical Properties." Active and Passive Electronic Components 20, no. 3 (1998): 169–87. http://dx.doi.org/10.1155/1998/16871.

Full text

Abstract:

The analysis of the infrared and ligand field spectra of COM2O4spinels reveals that the ionicity of these compounds varies in the following order aluminate > gallate > ferrite and chromite > rhodite and cobaltite. A linear relation has been established between the Δ(LO-TO)1splitting, Racah parameter and the ionic-covalent parameterSSp=ΣICP+tetra∑ICPocta. The influence of strong superexchange interactions on the optical spectrum of cobalt ferrites has been studied. The cation distribution has been established by EXAFS and XANES measurements. The cluster (CoFeO10)15–is characterized by a large MMCT transition Co2+→Fe3+at 1.65–1.7 eV (FWMH: 1.35–1.95 eV). The4A2→4T1(P) tetrahedral cobalt(II) in ferrimagnetic compounds is overlapped by the MMCT band. This study and the reinvestigation of the iron(III) electronic spectrum is ferrites may explain the magneto-optical properties of mixed cobalt-ferrites.

APA, Harvard, Vancouver, ISO, and other styles

UaCearnaigh, Deóis C., Roya Baghi, and Louisa J. Hope-Weeks. "Sol–gel synthesis of a series of first row d-block ferrites via the epoxide addition method." RSC Advances 6, no. 53 (2016): 48212–21. http://dx.doi.org/10.1039/c6ra05831k.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Peelamedu, Ramesh D., Rustum Roy, and Dinesh Agrawal. "Anisothermal reaction synthesis of garnets, ferrites, and spinels in microwave field." Materials Research Bulletin 36, no. 15 (2001): 2723–39. http://dx.doi.org/10.1016/s0025-5408(01)00743-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Srećkovic, M., V. Šijački-Žeravčić, N. Ivanović, et al. "Laser damage in ferrites of MnZn spinels and other possible interactions." Optics and Lasers in Engineering 27, no. 5 (1997): 507–22. http://dx.doi.org/10.1016/s0143-8166(96)00037-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Masrour, R., H. El Moussaoui, E. Salmani, et al. "Synthesis and Magnetic Properties of Bulk Ferrites Spinels Ni0.5Zn0.5Fe2O4: Experimental an Ab-Initio Study." Journal of Superconductivity and Novel Magnetism 27, no. 1 (2013): 177–81. http://dx.doi.org/10.1007/s10948-013-2234-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Ionescu, Daniela, and Gabriela Apreotesei. "Wave absorption control in the new designed photonic metamaterials with artificial opal." MATEC Web of Conferences 178 (2018): 04004. http://dx.doi.org/10.1051/matecconf/201817804004.

Full text

Abstract:

Photonic metamaterials consisting of artificial opal with magnetic inclusions were considered, used in controllable microwave electronic devices. The analyzed structures consist of matrices of SiO2 nanospheres (diameter 200 - 400 nm) with included clusters of ferrite spinels (MnxCo0.6-xZn0.4Fe2O4, NixCo0.6-xZn0.4Fe2O4, LaxCo0.6-xZn0.4Fe2O4, NdxCo0.6-xZn0.4Fe2O4) in interspherical nanospacing (4 ÷ 7% concentration). The ellipsoidal clusters are polycrystalline, with spatial dimensions of 20 – 30 nm and grains of 5 – 12 nm. A controlled wave absorption was obtained in these high inductivity structures. Evolution of the wave attenuation coefficient, α[dB/m], in function of the applied magnetic field and particle inclusion size, for different content of the magnetic ions in the ferrite inclusion, have been determined at frequencies around the samples ferromagnetic resonance, by structural simulation. The test configuration was: sample inside the rectangular waveguide, mode TE10, in the frequency range 24 ÷ 40 GHz. The polarizing magnetic field for the ferrites was tested in the range of 0 ÷ 20 kOe and minimized by modifying the structure. The metamaterial design optimization was realized, controllable by different parameters at structure level. The ferromagnetic resonance influence on the control process was pointed out and also the particular results and effects which can be induced by the resonant behavior.

APA, Harvard, Vancouver, ISO, and other styles

GILLOT, B., B. DOMENICHINI, P. TAILHADES, L. BOUET, and A. ROUSSET. "Reactivity of the submicron molybdenum ferrites towards oxygen and formation of new cation deficient spinels." Solid State Ionics 63-65 (September 1993): 620–27. http://dx.doi.org/10.1016/0167-2738(93)90169-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Wang, Wen Jie, Qing Jie Jiao, Chong Guang Zang, and Xiang Dong Zhu. "Study on the Absorption Properties of Spinel Type Ferrite Composite Coatings in the Low Frequency." Advanced Materials Research 415-417 (December 2011): 30–34. http://dx.doi.org/10.4028/www.scientific.net/amr.415-417.30.

Full text

Abstract:

In the present study magneto-polymer composite coatings are fabricated using nano Zn ferrite, Mn ferrite, Ni ferrite, Zn-Mn ferrite and Zn-Ni ferrite by spraying method. The complex permeabilities, Complex permittivities and microwave absorbing properties within the low frequency of these composites were characterized and investigated. The results showed that the magnetism of the mixed spinel ferrites ( Mn ferrite, Zn-Ni ferrite, Zn-Mn ferrite) are strong but the dielectric properties are weaker, while the magnetism of the normal spinel ferrites (Zn ferrite) is the weakest but provide with a big storage capability of electric energy. The absorbing characteristics of the spinel ferrites are better at 300 kHz-1.5GHz, with minimum absorption of 12.5 dB and the maximum absorption at 480MHz, 1050 MHz and 1400 MHz. The microwave absorbing property of the mixed spinel ferrite Zn-Mn ferrite is best having the RL value being -42.5 dB at 1400GHz.

APA, Harvard, Vancouver, ISO, and other styles

Manos, Donatos, Kleopatra Miserli, and Ioannis Konstantinou. "Perovskite and Spinel Catalysts for Sulfate Radical-Based Advanced Oxidation of Organic Pollutants in Water and Wastewater Systems." Catalysts 10, no. 11 (2020): 1299. http://dx.doi.org/10.3390/catal10111299.

Full text

Abstract:

Since environmental pollution by emerging organic contaminants is one of the most important problems, gaining ground year after year, the development of decontamination technologies of water systems is now imperative. Advanced oxidation processes (AOPs) with the formation of highly reactive radicals can provide attractive technologies for the degradation of organic pollutants in water systems. Among several AOPs that can be applied for the formation of active radicals, this review study focus on sulfate radical based-AOPs (SR-AOPs) through the heterogeneous catalytic activation of persulfate (PS) or peroxymonosulfate (PMS) using perovskite and spinel oxides as catalysts. Perovskites and spinels are currently receiving high attention and being used in substantial applications in the above research area. The widespread use of these materials is based mainly in the possibilities offered by their structure as it is possible to introduce into their structures different metal cations or to partially substitute them, without however destroying their structure. In this way a battery of catalysts with variable catalytic activities can be obtained. Due to the fact that Co ions have been reported to be one of the best activators of PMS, special emphasis has been placed on perovskite/spinel catalysts containing cobalt in their structure for the degradation of organic pollutants through heterogeneous catalysis. Among spinel materials, spinel ferrites (MFe2O4) are the most used catalysts for heterogeneous activation of PMS. Specifically, catalysts with cobalt ion in the A position were reported to be more efficient as PMS activators for the degradation of most organic pollutants compared with other transition metal catalysts. Substituted or immobilized catalysts show high rates of degradation, stability over a wider pH area and also address better the phenomena of secondary contamination by metal leaching, thus an effective method to upgrade catalytic performance.

APA, Harvard, Vancouver, ISO, and other styles

Gao, Fen, Dong Lin Zhao, and Zeng Min Shen. "Preparation and Microwave Absorbing Properties of Cu-Doped Ni-Zn Spinel Ferrites." Advanced Materials Research 105-106 (April 2010): 293–96. http://dx.doi.org/10.4028/www.scientific.net/amr.105-106.293.

Full text

Abstract:

Ni-Zn spinel ferrite and Cu-doped spinel ferrite were prepared by a conventional ceramic processing method. Microwave absorption, complex permittivity and permeability of the (Ni0.5Zn0.5)Fe2O4 and (Ni0.4Cu0.2Zn0.4)Fe2O4 spinel ferrites within the frequency range of 0.5-18 GHz were investigated. The reflection loss calculation results show that the Ni-Zn spinel ferrite and Cu-doped Ni-Zn spinel ferrite are good electromagnetic wave absorbers in the microwave range. The single layer (Ni0.4Cu0.2Zn0.4)Fe2O4 spinel ferrite absorber with a thickness of 9.2 mm achieved a reflection loss below -10 dB (90% absorption) at 0.5-2.3 GHz, and the minimum value is -35.63 dB at 1.1 GHz. When the first layer and second layer are (Ni0.5Zn0.5)Fe2O4 and (Ni0.4Cu0.2Zn0.4)Fe2O4 spinel ferrites respectively, the laminated absorbers with double spinel ferrite layers with a thickness of 3 mm achieved a reflection loss below -10 dB at 9.9-12.3 GHz, and the minimum value is -35.3 dB at 11.7 GHz.

APA, Harvard, Vancouver, ISO, and other styles

Sláma, Jozef, Martin Šoka, Anna Grusková, Alvaro Gonzalez, and Vladimír Jančárik. "Hopkinson Effect Study in Spinel and Hexagonal Ferrites." Journal of Electrical Engineering 62, no. 4 (2011): 239–43. http://dx.doi.org/10.2478/v10187-011-0038-7.

Full text

Abstract:

Hopkinson Effect Study in Spinel and Hexagonal Ferrites The magnetic susceptibility shows a Hopkinson peak just below the Curie temperature TC when heating the selected hexagonal and spinel ferrite samples. It is proposed that this peak can be associated with a transition from stable magnetic state to super-paramagnetic relaxation above the blocking temperature up to the TC. The Hopkinson effect results are compared with SEM micrographs of both studied hexagonal and spinel ferrites.

APA, Harvard, Vancouver, ISO, and other styles

Iacovita, Cristian, Gabriela Fabiola Stiufiuc, Roxana Dudric, et al. "Saturation of Specific Absorption Rate for Soft and Hard Spinel Ferrite Nanoparticles Synthesized by Polyol Process." Magnetochemistry 6, no. 2 (2020): 23. http://dx.doi.org/10.3390/magnetochemistry6020023.

Full text

Abstract:

Spinel ferrite nanoparticles represent a class of magnetic nanoparticles (MNPs) with enormous potential in magnetic hyperthermia. In this study, we investigated the magnetic and heating properties of spinel soft NiFe2O4, MnFe2O4, and hard CoFe2O4 MNPs of comparable sizes (12–14 nm) synthesized by the polyol method. Similar to the hard ferrite, which predominantly is ferromagnetic at room temperature, the soft ferrite MNPs display a non-negligible coercivity (9–11 kA/m) arising from the strong interparticle interactions. The heating capabilities of ferrite MNPs were evaluated in aqueous media at concentrations between 4 and 1 mg/mL under alternating magnetic fields (AMF) amplitude from 5 to 65 kA/m at a constant frequency of 355 kHz. The hyperthermia data revealed that the SAR values deviate from the quadratic dependence on the AMF amplitude in all three cases in disagreement with the Linear Response Theory. Instead, the SAR values display a sigmoidal dependence on the AMF amplitude, with a maximum heating performance measured for the cobalt ferrites (1780 W/gFe+Co), followed by the manganese ferrites (835 W/gFe+Mn), while the nickel ferrites (540 W/gFe+Ni) present the lowest values of SAR. The heating performances of the ferrites are in agreement with their values of coercivity and saturation magnetization.

APA, Harvard, Vancouver, ISO, and other styles

Hou, Yu Hua, Yu Jun Zhao, De Chang Zeng, Zhong Wu Liu, and Li Shi Wen. "First-Principles Investigation of the Electronic Structure and Magnetic Properties for Co-Doped Fe₃O₄." Materials Science Forum 654-656 (June 2010): 1678–81. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.1678.

Full text

Abstract:

The electronic structure and magnetic properties of the (Co1-xFex)Tet(CoxFe2-x)OctO4 spinels (x is deﬁned as the degree of inversion) scenario are investigated theoretically from first-principles, using generalized gradient approximation (GGA) method for the systems with strong coulomb correlations, which gives a correct description of the electronic structure. The GGA+U method gives an improved qualitative result compared with the GGA not only for the excited-state properties such as energy gaps but also for the ground-state properties such as magnetic moments and crystal parameters. The nominal valence of the transition metal elements and the ground state structure have been established based on the study of variation of the cation distribution (x=0.0, 0.25, 0.5, 0.75 and 1.0) over the tetrahedral and octahedral sites. The site-preference calculation on bulk systems indicates that Co2+ ions strongly prefer the octahedral B sites, and the electronic structure and magnetic properties of cobalt ferrites highly depend on the cation distributions even though the chemical composition of the compound does not change. The results are in good agreement with the available experimental data and most of the other theoretical results.

APA, Harvard, Vancouver, ISO, and other styles

Majid, Farzana, Amarah Nazir, Sadia Ata, et al. "Effect of Hydrothermal Reaction Time on Electrical, Structural and Magnetic Properties of Cobalt Ferrite." Zeitschrift für Physikalische Chemie 234, no. 2 (2020): 323–53. http://dx.doi.org/10.1515/zpch-2019-1423.

Full text

Abstract:

AbstractCobalt ferrite was synthesized by hydrothermal route in order to investigate the effect of hydrothermal reaction time on structural, magnetic and dielectric properties. The synthesized cobalt ferrite was characterized by X-ray diffraction, Fourier transform infrared and Vibrating-Sample Magnetometer (VMS). XRD data analysis confirmed the formation of cubic inverse spinel ferrite for complete time series as the high intensity peak corresponds to cubic normal spinel structure. The ionic radii, cation distribution among tetrahedral and octahedral sites, lattice parameters, X-ray density, bond lengths were also investigated cobalt ferrite prepared at different hydrothermal reaction time. The crystallite size was found to be in the range of 11.79–32.78 nm. Tolerance factor was near unity that also confirms the formation of cubic ferrites. VSM studies revealed the magnetic nature of cobalt ferrite. The coercivity (1076.3Oe) was observed for a sample treated for 11 h. The squareness ratio was 0.56 that is close to 0.5 which shows uniaxial anisotropy in cobalt ferrite. Frequency dependent dielectric properties i.e. dielectric constant, AC conductivity, tangent loss and AC resistivity are calculated with the help of Impedance Analyzer. Intrinsic cation vibration of cubic spinel ferrites are confirmed from FTIR analysis in the range of 400–4000 cm−1. In view of enhanced properties, this technique could possibly be used for the synthesis of cobalt ferrite for different applications.

APA, Harvard, Vancouver, ISO, and other styles

Seyyed Ebrahimi, S. A., and Z. Pishgahi Fard. "An Investigation on the Optimum Conditions for Preparation of Pure Mn-Mg-Zn Ferrite Powder." Key Engineering Materials 336-338 (April 2007): 699–702. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.699.

Full text

Abstract:

Manganese- Zinc ferrite is one of the most important spinel ferrites which is used in the electronics applications. These ferrites have an open lattice and can tolerate large amounts of the other metallic ions in their lattice. One of these divalent ions that can sit in the unit cell of Mn-Zn ferrites is Magnesium. Mn-Mg-Zn ferrites are new materials which is thought to be a good candidate for dielectric applications. In this work, a suitable relative values of raw materials for preparing pure Mn-Mg-Zn ferrite powder have been determined. It is carried out by using XRD experiments. The optimum temperature and time of calcination were also investigated by DTA/TGA, XRD and SEM techniques.

APA, Harvard, Vancouver, ISO, and other styles

Adarakatti, Shashidhar N., Veeresh S. Pattar, Prashant K. Korishettar, et al. "Synthesis, Structural and Electrical Studies of Li-Ni-Cu Nano Ferrites." Acta Chemica Iasi 26, no. 1 (2018): 1–12. http://dx.doi.org/10.2478/achi-2018-0001.

Full text

Abstract:

Abstract Li-Ni ferrite has gained great scientific elicit owing to of its unparalleled properties and applications. The copper doped Li-Ni ferrite has been synthesized by sucrose method. The structure was characterized by X-ray diffraction, which has confirmed the formation of single-phase spinel structure. X-ray diffraction and FTIR data reveals the formation of cubic structure phase. Unit cell parameters vary with copper content; overall variation of the unit cell parameters obeys Vegard’s law. The main absorption bands of spinel ferrite have appeared through IR absorption spectra recorded in the range of 300–700 cm−1. The copper concentration dependence of lattice parameters obeys Vegard’s law. DC electrical resistivity of the prepared samples decreases with increasing in the temperature which shows the semiconducting behaviour of all nano ferrites. The most prominent influence copper doping on the electrical properties of Li-Ni ferrites has been reported.

APA, Harvard, Vancouver, ISO, and other styles

PENCHAL REDDY, M., M. VENKATA RAMANA, N. RAMA MANOHAR REDDY, et al. "STRUCTURAL, ELECTRICAL AND MAGNETIC CHARACTERIZATION OF Ni–Cu–Zn SPINEL FERRITES." Modern Physics Letters B 25, no. 03 (2011): 211–22. http://dx.doi.org/10.1142/s0217984911025626.

Full text

Abstract:

Ni – Cu – Zn ferrite materials have been extensively used in multilayer chip inductors because of their remarkable properties at higher frequencies. In the present work, single phase Ni 0.35 Cu 0.05 Zn 0.60 Fe 1.98 O 4-δ ferrite, has been prepared by microwave sintered (MS) method. In comparison with the conventional sintering method (CS), the sintering temperature and time for this MS method were significantly reduced to 30 min and 950°C from 5 h and 1250°C for the CS process. The frequency dependence of the dielectric properties such as dielectric constant (ε'), dielectric loss ( tan δ) were studied. The temperature dependence of magnetic initial permeability (μi) was studied. The saturation magnetization was also studied as a function of magnetic field. These microwave sintered ferrites results were compared with the properties of ferrites prepared by conventional sintering method in normal heating. Microwave sintering improves structural as well as electromagnetic parameters measured and thus makes the ferrite more suitable in microwave applications and electromagnetic devices.

APA, Harvard, Vancouver, ISO, and other styles

Dippong, Thomas, Erika Andrea Levei, Iosif Grigore Deac, Emilia Neag, and Oana Cadar. "Influence of Cu2+, Ni2+, and Zn2+ Ions Doping on the Structure, Morphology, and Magnetic Properties of Co-Ferrite Embedded in SiO2 Matrix Obtained by an Innovative Sol-Gel Route." Nanomaterials 10, no. 3 (2020): 580. http://dx.doi.org/10.3390/nano10030580.

Full text

Abstract:

This paper presents the synthesis of metal doped Co ferrites, M0.2Co0.8Fe2O4 (M = Cu2+, Ni2+, and Zn2+) embedded in SiO2 matrix by an innovative sol-gel route. The structural and morphological characterization provided information about the crystalline phases, crystallite size, and the shape of the prepared ferrites. The thermal study depicted the thermal decomposition and stability of the obtained ferrites. X-ray diffraction indicated nanocrystalline ferrites with spinel structure and the lack of crystalline phase impurities, while Fourier transform infrared spectroscopy revealed the presence of functional groups in precursors and ferrite powders. The lattice parameters showed a gradual increase indicating a uniform distribution of divalent metal ions in the Co ferrite lattice. The crystallite size, magnetic moment, super-exchange and deflection of magnetic domain were influenced by the dopant metal ion. The room temperature magnetization indicated a ferromagnetic behavior of the ferrites annealed at 1000 °C and a superparamagnetic behavior of the ferrites annealed at 700 °C.

APA, Harvard, Vancouver, ISO, and other styles

Kodama, T., H. Kato, S. G. Chang, N. Hasegawa, M. Tsuji, and Y. Tamaura. "Decomposition of CO2 to carbon by H2-reduced Ni(II)- and Co(II)-bearing ferrites at 300 °C." Journal of Materials Research 9, no. 2 (1994): 462–67. http://dx.doi.org/10.1557/jmr.1994.0462.

Full text

Abstract:

Ni(II)- and Co(II)-bearing ferrites with different levels of metal substitution have been studied for CO2 decomposition. Ni2+ and Co2+ have been substituted for Fe2+ or Fe3+ in magnetite with the spinel type of crystal structure up to 14% and 26% for the mole ratio of Ni2+ and Co2+ to the total Fe contents, respectively. The metal substitution was corroborated by Mössbauer spectroscopy and XRD studies. They were activated in a flow of H2 gas to form oxygen-deficient ferrites with the spinel structure retained. The oxygen-deficient M(II)-bearing ferrites have been found to show high reactivity toward CO2 decomposition to carbon at 300 °C. The reactivity increased with the level of metal substitution and activation. The oxygens of CO2 were incorporated into the spinel structure and carbon was deposited on the surface of the ferrites. The deposited carbon was visible on dissolution of the ferrites used. The rate of decomposition on H2-activated Ni(II)-bearing ferrite with the mole ratio of 14% was 30 times as high as that of H2-activated magnetite.

APA, Harvard, Vancouver, ISO, and other styles

Al-Hilli, Muthafer F. "A comparison study of the Structural and magnetic properties of pure Ni metal and NiZnMn ferrite." Iraqi Journal of Physics (IJP) 17, no. 43 (2019): 18–25. http://dx.doi.org/10.30723/ijp.v17i43.418.

Full text

Abstract:

The magnetic properties of a pure Nickel metal and Nickel-Zinc-Manganese ferrites having the chemical formula Ni0.1(Zn0.4Mn0.6)0.9Fe2O4 were studied. The phase formation and crystal structure was studied by using x-ray diffraction which confirmed the formation of pure single spinel cubic phase with space group (Fd3m) in the ferrite. The samples microstructure was studied with scanning electron microstructure and EDX. The magnetic properties of the ferrite and nickel metal were characterized by using a laboratory setup with a magnetic field in the range from 0-500 G. The ferrite showed perfect soft spinel phase behavior while the nickel sample showed higher magnetic loss and coercivity.

APA, Harvard, Vancouver, ISO, and other styles

Galvão, Wesley S., Davino M. A. Neto, Rafael M. Freire, and P. B. A. Fechine. "Super-Paramagnetic Nanoparticles with Spinel Structure: A Review of Synthesis and Biomedical Applications." Solid State Phenomena 241 (October 2015): 139–76. http://dx.doi.org/10.4028/www.scientific.net/ssp.241.139.

Full text

Abstract:

The study of ceramic materials has attracted the attention of many researchers due to the possibility of their use in nanotechnology. The spinel ferrites form a large group of materials with a broad range of applications. Some examples include electronic devices such as high-frequency transformer cores, antenna rods, induction-tuners, among many others. However, when the ferritic materials display superparamagnetic behavior, their potential for biological applications like drug delivery, hyperthermia, resonance magnetic imaging and magnetic separation, become amazingly high. Therefore, the superparamagnetism is a characteristic strongly desired for spinel ferrites. Since this phenomenon is size-dependent, the methodologies to synthesize these materials has emerged as a crucial step in order to obtain the desired properties. In this regarding, several synthetic processes have been developed. For example, co-precipitation is a fast and cheap method to synthesize superparamagnetic spinel ferrites. However, methodologies involving microwave, ultrasound or polymers frequently result in these kind of materials. Therefore, this review brings a brief historic introduction about spinel ferrites as well as essential concepts to understand their structure and magnetic properties. In addition to this, recent advances in synthesis and applications of the superparamagnetic spinel ferrites are mentioned. Contents of Paper

APA, Harvard, Vancouver, ISO, and other styles

Ušáková, Mariana, Elemír Ušák, Martin Šoka, and Ján Lokaj. "The influence of selected ions on various characteristics of Nickel-Zinc ferrites." Journal of Electrical Engineering 69, no. 6 (2018): 449–53. http://dx.doi.org/10.2478/jee-2018-0072.

Full text

Abstract:

Abstract One of acknowledged methods remarkably improving structural, magnetic and electrical properties of spinel ferrite systems is the substitution of iron ions by some trivalent ions. In the family of spinel ferrites, thanks to its high saturation magnetization and electrical resistivity as well as low losses, the nickel-zinc ferrite is a very important magnetic material used in many applications in electrical engineering and electronics. The properties of these materials are in general dependent upon chemical composition, method of preparation, stoichiometry, sintering time, temperature as well as the atmosphere, etc. In this study the influence of appropriately selected ions (M = In3+, Nd3+, Dy3+ and Er3+), partly replacing Fe3+, on the microstructure and magnetic properties of spinel ferrite with the composition Ni0.42Zn0.58M0.02Fe1.98O4 fabricated by means of standard ceramic technology was investigated.

APA, Harvard, Vancouver, ISO, and other styles

Petrova, Elena G., Yana A. Shavshukova, Dzmitry A. Kotsikau, Kazimir I. Yanushkevich, Konstantin V. Laznev, and Vladimir V. Pankov. "Thermolysis of sprayed suspensions for obtaining highly spinel ferrite nanoparticles." Journal of the Belarusian State University. Chemistry, no. 1 (February 21, 2019): 14–21. http://dx.doi.org/10.33581/2520-257x-2019-1-14-21.

Full text

Abstract:

Thermal treatment of ferrite magnetic nanoparticles in NaCl matrix gives an opportunity to increase their specific magnetization with preservation of nanoscale size. Composite materials based on mixed ferrites Co0.65Zn0.35Fe2O4 and Mg 0.5Zn0.5Fe2O4 were synthesized by spray-drying of aqueous suspensions in presence of NaCl and annealed at 300 –900 °C. The microstructure and phase composition of nanoparticles before and after annealing were studied by scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction analysis and IR spectroscopy. The magnetic properties of nanoparticles were estimated using a ponderomotive method of measuring the specific magneti zation at room temperature in a magnetic field with an induction of 0.86 T. The increase of the annealing temperature up to 900 °C was established to lead to the increase in the specific magnetization of ferrites – from 32.79 to 91.3 emu/g (Co0.65Zn0.35Fe2O4) and from 2.76 to 22.31 emu/g (Mg 0.5 Zn 0.5Fe2O4) due to recrystallization processes and increase of crystallinity degree of the ferrites. Due to the NaCl insulating layer, the particle size increases just slightly (from ~ 10 nm before annealing to ~ 60 nm after annealing at 900 °C). This method is effective for substantial increase in specific magnetization of ferrite nanoparticles with preservation of their nanoscale size.

APA, Harvard, Vancouver, ISO, and other styles

Sangaa, Deleg, Baatartsogt Khongorzul, Enkhnaran Uyanga, Narmandakh Jargalan, Namsrai Tsogbadrakh, and Hideyuki Hirazawa. "An Overview of Investigation for Ferrite Magnetic Nanomaterial." Solid State Phenomena 271 (January 2018): 51–63. http://dx.doi.org/10.4028/www.scientific.net/ssp.271.51.

Full text

Abstract:

In recent time, interest to ferrite magnetic nanomaterials has considerably grown mainly due to their much promising medical and biological applications. The spinel ferrite powder samples having high heat generation ability in AC magnetic field was studied for application to hyperthermia treatment of cancer tumor. These properties of ferrites are strongly depending on their chemical composition, ion distribution, spin orientation and method of preparation in general and crystal structure in particular nature of the material. In this study, several samples of ferrite magnetic structures were investigated by neutron diffraction. The explanation of the mechanism to occurs the heat generation ability in the magnetic materials and the electronic and magnetic states of ferrite-spinel – type structures were theoretically defined by the first-principles calculations within the framework of DFT.

APA, Harvard, Vancouver, ISO, and other styles

Walters, I., R. Shende, and J. A. Puszynski. "Hydrogen Production from Thermochemical Water-Splitting Using Ferrites Prepared by Solution Combustion Synthesis." Advances in Science and Technology 91 (October 2014): 32–38. http://dx.doi.org/10.4028/www.scientific.net/ast.91.32.

Full text

Abstract:

Currently, there are several methods to produce spinel ferrite powder material such as sol-gel synthesis, self-propagating high-temperature synthesis (SHS), aerosol spray pyrolysis, and solution combustion synthesis (SCS). These methods have been shown to produce nominally phase pure ferrites for use in hydrogen generation by thermochemical water-splitting. Among these methods, the ferrites derived by SCS have not been fully investigated for hydrogen generation from thermochemical water-splitting. SCS, in general, has several advantages such as it being a simple synthesis that can be done relatively quickly and produces materials with high specific surface area. In this study, nickel, zinc, cobalt, and manganese ferrites were synthesized using SCS and analyzed by XRD, BET, and SEM. Each ferrite material was placed inside an Inconel tubular reactor and five consecutive thermochemical cycles to determine hydrogen production. The regeneration and water-splitting temperatures were performed with water-splitting and regeneration temperatures of 900°C and 1100°C, respectively. Nickel ferrite produced significantly higher average hydrogen volume as compared to the other ferrites over the five thermochemical cycles. However, all four ferrites showed a decrease in hydrogen volume generation with increase in consecutive water-splitting cycle, which could be due to the grain growth as observed by BET and SEM analyses.

APA, Harvard, Vancouver, ISO, and other styles

GHOSH, A., M. SATALKAR, S. RATHOD, et al. "SOFT MAGNETIC PROPERTIES OF Mg0.7-xNi0.3ZnxFe2O4 FERRITES SYNTHESIZED BY SOL-GEL AUTO-COMBUSTION TECHNIQUE WITHOUT POST-PREPARATION THERMAL TREATMENT." International Journal of Modern Physics: Conference Series 22 (January 2013): 28–34. http://dx.doi.org/10.1142/s2010194513009896.

Full text

Abstract:

Single phase nanocrystalline soft magnetic Mg 0.7-x Ni 0.3 Zn x Fe 2 O 4, ferrites with x = 0.0 − 0.7 were prepared by sol gel auto-combustion method. X-ray diffraction confirms the formation of single phase nano-crystalline cubic spinel ferrites with average grain diameter ranging between 12.9 nm to 23.9 nm. Formation of the ferrite phase without subsequent heat treatment makes sol-gel auto combustion technique especially suitable and economical for the large scale industrial production of the nano-crystalline ferrites for multilayer chip inductor applications (MLCI). Both, lattice parameter and X-ray density shows a linear increase with increasing Zn 2+ concentration, attributed to the difference in ionic radii and density of Mg and Zn . Increase in Zn content enhances the soft magnetic behavior, exhibiting linear decrease of coercivity from 122.34 Oe to 72.45 Oe, explained by increase of density with Zn addition. The maximum magnetization (Mmax)increases up to 0.106 Tesla (for x = 0.4) and. then decreases with increase of Zn content, discussed on the basis of increase of the occupancy of A-site in spinel ferrite by non-magnetic Zn 2+ ion.

APA, Harvard, Vancouver, ISO, and other styles

Hussain, A., S. Akbar Tahir, N. Ahmad, M. Hashim, A. Bashir Ziya, and S. Noreen. "A study on microstructure and magnetic properties of nanostructured CoxNi1-xMn0.5Fe1.5O4(x=0,0.25,0.5,0.75,1) spinel ferrites." Revista Mexicana de Física 67, no. 3 May-Jun (2021): 527. http://dx.doi.org/10.31349/revmexfis.67.527.

Full text

Abstract:

A low-temperature synthesis of novel nanostructured CoxNi1-xMn0.5Fe1.5O4(x=0,0.25,0.5,0.75,1) ferrites was carried out by sol-gel auto-combustion technique. The obtained nanostructured ferrites were investigated by employing the techniques of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometry (VSM). The XRD diffractograms of the prepared ferrites revealed the formation of a spinel phase with face centered cubic (fcc) structure belonging to Fd- m space group. The average lattice parameter ‘a’ of ferrites exhibited a rise versus a rise in Co2+ concentration in accordance with the Vegard’s law. The SEM investigation of NiMn0.5Fe1.5O4 powder revealed an existence of octahedral-shaped morphology of ferrite grains. The TEM investigation of NiMn0.5Fe1.5O4 powder showed nanostructures of ferrite particles with sizes consistent with the crystallite sizes as estimated by Debye-Scherer’s formula. An EDX spectrum of NiMn0.5Fe1.5O4 powder confirmed its elemental composition. The M-H hysteresis loops recorded by VSM at room temperature revealed a dependence of coercivity (Hc), maximum magnetization (Mmax) and retentivity (Mr) on Co2+concentration. Due to the shape dependence of M-H loops on Co2+ concentration in compounds enabled their candidature for applications in memory devices and magnetic sensors.

APA, Harvard, Vancouver, ISO, and other styles

Ren, Gui Hua, and Zhi Song Yu. "Synthesis of Monodisperse Fe₃O₄ and MnFe₂O₄ Nanospheres by Using a Solvothermal Reduction Method." Solid State Phenomena 181-182 (November 2011): 393–96. http://dx.doi.org/10.4028/www.scientific.net/ssp.181-182.393.

Full text

Abstract:

The spinel ferrites, MFe2O4(where M=Fe, Mn, Co, Ni, Zn, Mg, etc.) have attracted considerable interest during the last few decades due to their potential applications in high frequency transformers, filters, high density storage devices, and microwave applications. In the latest several years, many synthesis technologies such as sol-gel, auto-combustion, thermal decomposition methods and hydrothermal reaction have been developed to prepare spinel ferrite nanoparticles. In this paper, the spinel ferrites Fe3O4and MnFe2O4nanoparticles were synthesized by using a solvothermal reduction method. X-ray diffraction (XRD) and Raman analysis shows that all the peaks are close to the data for Fe3O4and MnFe2O4, indicating the prepared particles are single phase. The scan electronic microscopy (SEM) shows that the prepared Fe3O4and MnFe2O4are monodisperse nanospheres and with the average size of around 300nm.

APA, Harvard, Vancouver, ISO, and other styles

Owolabi, Taoreed O., Tawfik A. Saleh, Olubosede Olusayo, Miloud Souiyah, and Oluwatoba Emmanuel Oyeneyin. "Modeling the Specific Surface Area of Doped Spinel Ferrite Nanomaterials Using Hybrid Intelligent Computational Method." Journal of Nanomaterials 2021 (August 18, 2021): 1–13. http://dx.doi.org/10.1155/2021/9677423.

Full text

Abstract:

Spinel ferrites nanomaterials are magnetic semiconductors with excellent chemical, magnetic, electrical, and optical properties which have rendered the materials useful in many technological driven applications such as solar hydrogen production, data storage, magnetic sensing, converters, inductors, spintronics, and catalysts. The surface area of these nanomaterials contributes significantly to their targeted applications as well as the observed physical and chemical features. Experimental doping has shown a great potential in enhancing and tuning the specific surface area of spinel ferrite nanomaterials while the attributed experimental challenges call for viable theoretical model that can estimate the surface area of doped spinel ferrite nanomaterials with high degree of precision. This work develops stepwise regression (STWR) and hybrid genetic algorithm-based support vector regression (GBSVR) intelligent model for estimating specific surface area of doped spinel ferrite nanomaterials using lattice parameter and the size of nanoparticle as descriptors to the models. The developed hybrid GBSVR model performs better than STWR model with the performance improvement of 7.51% and 22.68%, respectively, using correlation coefficient and root mean square error as performance metrics when validated with experimentally measured specific surface area of doped spinel ferrite nanomaterials. The developed GBSVR model investigates the influence of nickel, yttrium, and lanthanum nanoparticles on the specific surface area of different classes of spinel ferrite nanomaterials, and the obtained results agree excellently well with the measured values. The accuracy and precision characterizing the developed model would be of immense importance in enhancing specific surface area of doped spinel ferrite nanomaterial prediction with circumvention of experimental stress coupled with reduced cost.

APA, Harvard, Vancouver, ISO, and other styles

Anjaneyulu, T., P. Narayana Murthy, S. M. Rafi, S. Bademiya, and G. Samuel John. "Effect on Magnetic Properties of Zinc Doped Nano Ferrites Synthesized by Precursor or Method." International Letters of Chemistry, Physics and Astronomy 19 (October 2013): 37–43. http://dx.doi.org/10.18052/www.scipress.com/ilcpa.19.37.

Full text

Abstract:

Nanocrystalline Cu-Zn ferrites have been synthesized using precursor method. Cu-Zn ferrites were formed at low temperature without any impurities. The particle sizes were observed to decrease from 60 nm to 50 nm with increasing non-magnetic Zn doping. Cu is used to decrease the sintering temperature. The X-ray diffraction (XRD) and IR analysis of Cu-Zn revealed the formation of Single-Phase Spinel structure at very low annealing temperature. The particle sizes observed from XRD is very well in agreement with SEM analysis. Cu-Zn ferrite nanoparticles were observed to be dependent on the particle size. Saturation (Ms) and Remanence (Mr) magnetization of ferrites increases due to the modifications occurred among the A-B, A-A and B-B interactions of Spinel structure. The Coercive force (Hc) decreases with increase of Zn ions concentration.

APA, Harvard, Vancouver, ISO, and other styles

FU, X. L., Q. K. XING, Z. J. PENG, et al. "MICROSTRUCTURAL AND ELECTROMAGNETIC PROPERTIES OF Mn–Zn FERRITES WITH LOW MELTING-POINT NONMAGNETIC Sb3+ IONS." International Journal of Modern Physics B 27, no. 04 (2012): 1350003. http://dx.doi.org/10.1142/s0217979213500033.

Full text

Abstract:

The doping effects of low melting-point nonmagnetic Sb 3+ ions on the microstructure and electromagnetic properties of Mn–Zn ferrites were studied. All the samples were prepared by traditional ceramic technique. According to the investigation on the microstructure, it was found that all the samples consisted of ferrite phases with typical spinel cubic structure, and with increasing doping content of Sb 3+ ions, the lattice constant of the ferrites decreased but the grain size increased; the elemental analysis taken on the ferrite grain and grain boundary indicated that a portion of Sb 3+ ions entered into the ferrite lattice. Through the measurement of magnetic properties, it was revealed that, the saturation magnetization and initial permeability of the samples rose with small doping content of Sb 3+ ions but decreased with additional Sb 3+ doping; the Curie temperature decreased monotonously with Sb 3+ doping; and the coercivity rose with increasing doping content of Sb 3+ ions. The analysis of dielectric properties indicated that the dielectric constant of the doped Mn – Zn ferrites increased with increasing doping content of Sb 3+ ions.

APA, Harvard, Vancouver, ISO, and other styles

Thorat, Lankeshwar M., Digambar Y. Nadargi, Mohaseen S. Tamboli, et al. "Co2+ Substituted Spinel MgCuZn Ferrimagnetic Oxide: A Highly Versatile Electromagnetic Material via a Facile Molten Salt Route." Nanomaterials 10, no. 12 (2020): 2333. http://dx.doi.org/10.3390/nano10122333.

Full text

Abstract:

We report on the electromagnetic properties of Co2+ substituted spinel MgCuZn ferrites developed via a facile molten salt synthesis (MSS) route. The choice of synthesis route in combination with cobalt substitution led to strong electromagnetic properties such as high saturation magnetization (i.e., 63 emu/g), high coercivity (17.86 gauss), and high initial permeability (2730), which are beneficial for the multilayer chip inductor (MLCI) application. In a typical process, the planned ferrites were synthesized at 800 °C using sodium chloride as a growth inhibitor, with dense morphology and irregularity in the monolithicity of the grains. The compositional analysis of as-prepared ferrite confirms the presence of desired elements with their proportion. The crystallite size (using X-ray diffraction (XRD) analysis) for different samples varies in the range of 49–51 nm. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis showcases the compact morphology of the developed samples, which is typical in the ferrite system. The dielectric properties (dielectric-loss and dielectric-constant) in the frequency range of 100Hz–1MHz suggest normal dielectric distribution according to interfacial polarization from Maxwell–Wagner. From the developed ferrites, upon comparison with a low dielectric loss with high permeability value, Mg-Cu-Zn ferrite with Co = 0.05 substitution proved to be a stronger material for MLCIs with high-performance applications.

APA, Harvard, Vancouver, ISO, and other styles

Gatelyte, Aurelija, Darius Jasaitis, Aldona Beganskiene, and Aivaras Kareiva. "Sol-Gel Derived Ferrites: Synthesis and Characterization." Advanced Materials Research 222 (April 2011): 235–38. http://dx.doi.org/10.4028/www.scientific.net/amr.222.235.

Full text

Abstract:

In the present work, the sinterability and formation of nanosized yttrium iron garnet (Y3Fe5O12), yttrium perovskite ferrite (YFeO3), cobalt, nickel and zinc iron spinel (CoFe2O4, NiFe2O4 and ZnFe2O4, respectively) powders by an aqueous sol-gel processes are investigated. The phase purity of synthesized nano-compounds was characterized by powder X-ray diffraction analysis (XRD). The microstructural evolution and morphological features of obtained transition metal ferrites were studied by scanning electron microscopy (SEM). The possible application of these nanosized transition metal ferrites as ceramic pigments was demonstrated.

APA, Harvard, Vancouver, ISO, and other styles

Kopayev, A. V., V. V. Mokljak, I. M. Gasyuk, I. P. Yaremiy, and V. V. Kozub. "Structure Ordering in Mg-Zn Ferrite Nanopowders Obtained by the Method of Sol-Gel Autocombustion." Solid State Phenomena 230 (June 2015): 114–19. http://dx.doi.org/10.4028/www.scientific.net/ssp.230.114.

Full text

Abstract:

The Mg1-xZnxFe2O4 (x = 0, 0.2, 0.44, 0.5, 0.6) ferrite nanopowders of the spinel structure obtained by the sol-gel autocombustion (SGA) have been investigated using the X-ray diffraction and Mössbauer methods. The proofs were revealed verifying the potential occurrence of structural heterogeneity as solid solutions of various compositions of ferrites can be observed in a single phase system. In case of magnesium–zinc replacement, structural components occur, having different distribution of ferrum cations in crystallographic positions of the spinel lattice. The abnormal strength of nuclear effective fields is the indicator thereof. In addition, paramagnetic and superparamagnetic components were discovered there as well. This effect cannot be observed in the ferrite synthesis by the ceramic method.

APA, Harvard, Vancouver, ISO, and other styles

Thangjam, Biju, and Ibetombi Soibam. "Comparative Study of Structural, Electrical, and Magnetic Behaviour of Ni-Cu-Zn Nanoferrites Sintered by Microwave and Conventional Techniques." Journal of Nanomaterials 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/5756197.

Full text

Abstract:

Ni0.8-xCuxZn0.2Fe2O4 spinel type ferrite nanoparticles have been synthesized by citrate precursor method. These nanoparticles were then given heat treatment using microwave and conventional sintering techniques. Various characterizations using X-ray powder diffraction (XRD), scanning electron microscope (SEM), LCR meter, and B-H loop tracer were carried out on the sintered specimens. The XRD spectra of these ferrites confirmed the formation of spinel structure. The average crystallite size calculated using Scherrer’s formula was found to be in the nanometer range, its value varying from 33 nm to 39 nm. Microwave sintered samples exhibited superior electrical and magnetic behaviour over their conventionally sintered counterparts. Feasibility of low temperature synthesis and promising properties will render these ferrites suitable for multilayer chip inductor applications.

APA, Harvard, Vancouver, ISO, and other styles

Shafa, M., M. Y. Naz, M. R. Ahmad, Y. Khan, and A. Ghaffar. "Structural Study on Nano-crystals of Spinel Mgx-Zn1-X-Fe2O4 Ferrite with and without Calcination." High Temperature Materials and Processes 37, no. 1 (2018): 89–95. http://dx.doi.org/10.1515/htmp-2016-0037.

Full text

Abstract:

AbstractThis study investigated a series of single phase Mgx-Zn1-x-Fe2O4 spinel ferrites, prepared using co-precipitation technique and sintered at 600 °C. The X-ray diffraction (XRD) patterns of the ferrite samples revealed the formation of impurity free single phase spinel structures. The formation of ferrite phases and face centered cubic structures was confirmed at Bragg angles of 35.9°, 54.3° and 62.7°. The lattice parameter increased with an increase in ‘x’ content in the ferrite composition. The grain size, estimated from SEM micrographs, was found in the range of 0.5–2 mµ. The lattice parameter of the ferrite samples exhibited an initial increase upto a certain extent, thereafter suddenly dropped down due to fracturing and re-welding processes. Overall, the lattice parameter ‘a’ varied from 0.80 to 0.85 nm, crystallite size from 34 to 80 nm, unit cell volume from 0.528 × 10−21 to 0.62 × 10−21 cm3 and X-ray density from 5.8 to 4.5 g/cm3.

APA, Harvard, Vancouver, ISO, and other styles

Jovalekic, Cedomir, Aleksandar Nikolic, Maja Gruden-Pavlovic, and Miodrag Pavlovic. "Mechanochemical synthesis of stoichiometric nickel and nickel-zinc ferrite powders with Nicolson-Ross analysis of absorption coefficients." Journal of the Serbian Chemical Society 77, no. 4 (2012): 497–505. http://dx.doi.org/10.2298/jsc110302186j.

Full text

Abstract:

The interest in finding new methods for preparation of nickel ferrite (NiFe2O4) and nickel-zinc ferrite (NixZn1-xFe2O4) powders has recently increased, due to the fact that physical and chemical properties of these soft magnetic materials depend strongly on the preparation conditions. In this paper, powder samples of ferrites were obtained by: 1) classic sintering procedure (NixZn1-xFe2O4, x = 0.9) and 2) planetary mill synthesis (both NiFe2O4 and NixZn1-xFe2O4). Mechanochemical reaction leading to the formation of NixZn1-xFe2O4 (x = 1 and 0.9) spinel phase was monitored by SEM, TEM, and XRD. Values of the real and imaginary parts of permittivity and permeability were measured for the obtained nickel and nickel-zinc ferrite samples in the 7-12 GHz frequency range. Based on the obtained results, the EMR absorption coefficients were calculated for all three sample types. It has been concluded that the method of preparation and the final particle size influence the EMR absorption coefficient of nickel and nickel-zinc ferrites.

APA, Harvard, Vancouver, ISO, and other styles

Ma, Rui Ting, San Kuan Chen, and Gang Zhang. "Influences of Nd³⁺ Ions Substitution on the Structure and Electromagnetic Properties of the Nanocrystalline Co_0.5Zn_0.5Fe₂O₄ Ferrite." Advanced Materials Research 194-196 (February 2011): 524–28. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.524.

Full text

Abstract:

The spinel nanocrystalline Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite was prepared by polyacrylamide gel method. Influences of Nd3+ ions substitution on the microstructural and electromagnetic properties for the Co0.5Zn0.5Fe2O4 ferrites had been systematically investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and wave-guide method. The results showed that the Nd3+ ions can replace Fe3+ ions and adjust lattice parameters. The average size of the Co0.5Zn0.5Fe2O4 and Co0.5Zn0.5Nd0.05Fe1.95O4 particles were identified to be about 50nm and 60nm by TEM, respectively. The complex permittivity (=ε′-jε″) and complex permeability (=μ′-jμ″) for the composites had been measured in the frequency range of 8.2-12.4GHz. The results showed that the Co0.5Zn0.5Fe2O4 and Co0.5Zn0.5Nd0.05Fe1.95O4 ferrites had both dielectric loss and magnetic loss. The dielectric loss tangent (tgδε) and magnetic loss tangent (tgδm) for the Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite were obviously higher than those of the Co0.5Zn0.5Fe2O4. The maximal value of tgδε and tgδm for the Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite was around 0.30 at 12.4GHz and 0.16 at 10.8GHz, respectively.

APA, Harvard, Vancouver, ISO, and other styles

Tamaura, Y., T. Katsura, S. Rojarayanont, T. Yoshida, and H. Abe. "Ferrite Process; Heavy Metal Ions Treatment System." Water Science and Technology 23, no. 10-12 (1991): 1893–900. http://dx.doi.org/10.2166/wst.1991.0645.

Full text

Abstract:

The principle of the “Ferrite Process”, heavy metal ions treatment system, and the practically operated systems are presented. In the “Ferrite Process”, the heavy metal ions are incorporated into the lattice points of the ferrites in the course of the formation of the spinel structure by the oxidation of the Fe(II) ions. The ferrite formation reaction proceeds in two paths depending on the reaction pH; 1) the green rust path (pH 7-10), and 2) the γ-FeO(OH) path (pH 10.5-11). The mole ratio of the heavy metal ions incorporated into the lattice points to the Fetotal in the ferrites depends on the reaction pH and the mol ratio of the heavy metal ions in the reaction solution and to the Fe(II) ions added to the reaction solution. Ferrite Process is now practically adopted to the treatment of the laboratory waste waters at the universities and the institutes in Japan, to the treatment of the plating waste waters, and to the treatment of branching mine drainage waters. Since the ferrite sludge has a strong magnetic property, it is reused as a useful magnetic material.

APA, Harvard, Vancouver, ISO, and other styles

Xing, Qing Kai, Zhi Jian Peng, Cheng Biao Wang, Zhi Qiang Fu, and Xiu Li Fu. "Doping Effect of W⁶⁺ Ions on Microstructural and Magnetic Properties of Mn-Zn Ferrites." Key Engineering Materials 512-515 (June 2012): 1408–11. http://dx.doi.org/10.4028/www.scientific.net/kem.512-515.1408.

Full text

Abstract:

Mn-Zn ferrites with different doping contents of W6+ ions were prepared by using standard ceramic technique. The microstructure and magnetic properties of the as-prepared Mn-Zn ferrites were investigated. It was found that all the samples with different contents of W6+ ions consisted of ferrite phase of typical spinel cubic structure. With increasing doping content of W6+ ions, the lattice constant of the ferrites decreased but the grain size increased. Through the measurement of magnetic properties, it was revealed that the saturation magnetization and initial permeability of the samples increased with small doping content of W6+ ions but decreased with additional doping, and the Curie temperature decreased monotonously with W6+ ion doping.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!