Journal articles: 'Ferrites spinel'

1

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.

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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.

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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.

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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.

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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 (July 1, 2011): 239–43. http://dx.doi.org/10.2478/v10187-011-0038-7.

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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.

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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.

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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

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5

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 (February 1994): 462–67. http://dx.doi.org/10.1557/jmr.1994.0462.

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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.

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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.

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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.

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Iacovita, Cristian, Gabriela Fabiola Stiufiuc, Roxana Dudric, Nicoleta Vedeanu, Romulus Tetean, Rares Ionut Stiufiuc, and Constantin Mihai Lucaciu. "Saturation of Specific Absorption Rate for Soft and Hard Spinel Ferrite Nanoparticles Synthesized by Polyol Process." Magnetochemistry 6, no. 2 (May 29, 2020): 23. http://dx.doi.org/10.3390/magnetochemistry6020023.

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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.

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8

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.

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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.

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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 (December 1, 2018): 449–53. http://dx.doi.org/10.2478/jee-2018-0072.

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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.

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10

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.

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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.

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11

Adarakatti, Shashidhar N., Veeresh S. Pattar, Prashant K. Korishettar, Bhagyashri V. Grampurohit, Ravindra G. Kharabe, Akshay B. Kulkarni, Shridhar N. Mathad, Chidanandayya S. Hiremath, and Rangappa B. Pujar. "Synthesis, Structural and Electrical Studies of Li-Ni-Cu Nano Ferrites." Acta Chemica Iasi 26, no. 1 (July 1, 2018): 1–12. http://dx.doi.org/10.2478/achi-2018-0001.

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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.

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12

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 (March 1, 2020): 1589–604. http://dx.doi.org/10.1166/jnn.2020.17132.

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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.

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13

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 (March 22, 2020): 580. http://dx.doi.org/10.3390/nano10030580.

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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.

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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.

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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.

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de la Torre, Ernesto, Ana Lozada, Maricarmen Adatty, and Sebastián Gámez. "Activated Carbon-Spinels Composites for Waste Water Treatment." Metals 8, no. 12 (December 16, 2018): 1070. http://dx.doi.org/10.3390/met8121070.

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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.

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Majid, Farzana, Amarah Nazir, Sadia Ata, Ismat Bibi, Hafiz Shahid Mehmood, Abdul Malik, Adnan Ali, and Munawar Iqbal. "Effect of Hydrothermal Reaction Time on Electrical, Structural and Magnetic Properties of Cobalt Ferrite." Zeitschrift für Physikalische Chemie 234, no. 2 (February 25, 2020): 323–53. http://dx.doi.org/10.1515/zpch-2019-1423.

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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.

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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.

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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.

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PENCHAL REDDY, M., M. VENKATA RAMANA, N. RAMA MANOHAR REDDY, K. V. SIVA KUMAR, R. RAMA KRISHNA REDDY, W. MADHURI, K. SIVA KUMAR REDDY, P. SREEDHARA REDDY, and V. R. K. MURTHY. "STRUCTURAL, ELECTRICAL AND MAGNETIC CHARACTERIZATION OF Ni–Cu–Zn SPINEL FERRITES." Modern Physics Letters B 25, no. 03 (January 30, 2011): 211–22. http://dx.doi.org/10.1142/s0217984911025626.

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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.

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GHOSH, A., M. SATALKAR, S. RATHOD, S. P. NAG, P. VYAS, N. KANE, N. GHODKE, R. PRASAD, and R. DWIVEDI. "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.

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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.

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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.

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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.

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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.

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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.

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Wolska, Emillia. "Defect Structures in Spinel Ferrites." Defect and Diffusion Forum 134-135 (March 1996): 89–0. http://dx.doi.org/10.4028/www.scientific.net/ddf.134-135.89.

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Darshane, V. S., S. S. Lokegaonkar, and S. G. Oak. "Catalysis by Oxidic Spinel Ferrites." Le Journal de Physique IV 07, no. C1 (March 1997): C1–683—C1–684. http://dx.doi.org/10.1051/jp4:19971280.

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Narang, Sukhleen Bindra, and Kunal Pubby. "Nickel Spinel Ferrites: A review." Journal of Magnetism and Magnetic Materials 519 (February 2021): 167163. http://dx.doi.org/10.1016/j.jmmm.2020.167163.

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CHEN, C., M. GREENBLATT, and J. WASZCZAK. "Lithium insertion into spinel ferrites." Solid State Ionics 18-19 (January 1986): 838–46. http://dx.doi.org/10.1016/0167-2738(86)90273-0.

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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 (November 29, 2019): 18–25. http://dx.doi.org/10.30723/ijp.v17i43.418.

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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.

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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 (April 30, 2021): 527. http://dx.doi.org/10.31349/revmexfis.67.527.

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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.

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Исаев, И. М., В. Г. Костишин, В. В. Коровушкин, Д. В. Салогуб, Р. И. Шакирзянов, А. В. Тимофеев, and А. Ю. Миронович. "Магнитные и радиопоглощающие свойства поликристаллического феррита-шпинели Li-=SUB=-0.33-=/SUB=-Fe-=SUB=-2.29-=/SUB=-Zn-=SUB=-0.21-=/SUB=-Mn-=SUB=-0.17-=/SUB=-0-=SUB=-4-=/SUB=-." Журнал технической физики 91, no. 9 (2021): 1376. http://dx.doi.org/10.21883/jtf.2021.09.51217.74-21.

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Polycrystalline spinel ferrites of the composition Li0.33Fe2.29Zn0.21Mn0.17O4 were synthesized by using the ceramic technology method at sintering temperatures of 950 ° C, 1000 ° C, 1050 ° C, and 1100 ° C. Magnetic hysteresis loops and magnetic permeability of the experimental samples were studied in the range of magnetic fields of -400–400 A/m. In the frequency range of 0.01–7.0 GHz, the behavior of the complex dielectric and complex magnetic permeability, as well as the reflection coefficient on a metal plate, are investigated. It was found that the optimal sintering temperature range for synthesized ferrites is from 1050 ° C to 1100 ° C. It is shown that the spinel ferrite Li0.33Fe2.29Zn0.21Mn0.17O4 intensely absorbs electromagnetic radiation in the frequency range from 0.05 to 7.0 GHz. Possibilities of practical application of the obtained results are discussed.

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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 (September 9, 2014): 1450165. http://dx.doi.org/10.1142/s0217979214501653.

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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.

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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.

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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.

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AI, LUNHONG, JING JIANG, and HEJUN GAO. "EFFECT OF SAMARIUM DOPING ON THE STRUCTURAL AND MAGNETIC PROPERTIES OF THE LITHIUM–NICKEL FERRITE." Modern Physics Letters B 22, no. 21 (August 20, 2008): 2027–33. http://dx.doi.org/10.1142/s0217984908016698.

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Sm -doped Li – Ni ferrites were synthesized by a soft chemistry method. The effects of Sm -doping on the structural and magnetic properties of the Li – Ni ferrites were investigated. The structural, morphological and magnetic properties of the ferrite samples were characterized by X-ray diffractometer (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The results revealed that the Sm -doped samples had the single spinel phase at low Sm content. The increase in Sm content increased the lattice parameter and decreased the particle sizes. The magnetic properties of the Sm -doped Li – Ni ferrites were strongly affected by Sm content. The saturation magnetization decreased, while coercivity increased with increasing Sm content.

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Ranganath, Kalluri V. S., Mahendra Sahu, Melad Shaikh, Pramod Kumar Gavel, Kiran Kumar Atyam, Santimoy Khilari, and Pradip Das. "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.

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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.

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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.

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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.

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Varalaxmi, N., K. V. Sivakumar, and Hardev Singh Virk. "Studies on Internal Friction and Curie Temperature of NiMgCuZn Spinel Ferrites for Micro-Inductor Applications." Solid State Phenomena 241 (October 2015): 202–25. http://dx.doi.org/10.4028/www.scientific.net/ssp.241.202.

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Three series of NiMgCuZn ferrites were prepared by conventional double sintering ceramic process. The formation of single phase in these ferrites was confirmed by X-ray diffraction. A brief review of the important investigations carried out on the internal friction behaviour of NiMgCuZnFe2O4, in the temperature range 40oC to 360oC, has been reported. In the present investigation, the composite piezoelectric resonator method has been used. The effect of compositional changes of ferrites on Curie temperature and internal friction are reported. Results and discussions on the temperature variation of internal friction of the three series of NiMgCuZnFe2O4samples are discussed. In all the series studied, only single stress induced relaxation peaks are observed. These studies were carried out to develop a ferrite composition for their use as core materials for microinductor applications. The results are explained in the light of structural phase transitions.

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35

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.

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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.

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36

Flores, Ariadna, Karina Nesprias, Paula Vitale, Julia Tasca, Araceli Lavat, Nora Eyler, and Adriana Cañizo. "Heterogeneous Photocatalytic Discoloration/Degradation of Rhodamine B with H2O2 and Spinel Copper Ferrite Magnetic Nanoparticles." Australian Journal of Chemistry 67, no. 4 (2014): 609. http://dx.doi.org/10.1071/ch13435.

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The discoloration/degradation of the artificial dye Rhodamine B (RhB) was investigated using advanced oxidation technologies. Aqueous solutions of RhB containing spinel copper ferrites (CuFe2O4) as a heterogeneous catalyst were exposed to UV irradiation/hydrogen peroxide. Under these experimental conditions the discoloration/degradation of RhB is strongly promoted by copper ferrites, reaching 95 % discoloration of the dye in 10 min and 97 % degradation in 200 min. The influence of the catalyst amount, H2O2 concentration, light source, and UV light intensity were studied. Optimum concentrations of H2O2 and catalyst dosage were found for the RhB degradation reaction. The catalyst had high magnetic sensitivity under an external magnetic field, which allowed its magnetic separation from water avoiding secondary pollution processes, and its recycling. A markedly synergetic effect of spinel copper ferrite and UV light irradiation was observed for the RhB discoloration/degradation with H2O2 as a green oxidant.

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Huang, Kai, Xiansong Liu, Shuangjiu Feng, Jiangying Yu, Xiaofei Niu, Farui Lv, and Xing Huang. "Structural and Magnetic Properties of Cr-Substituted NiCuZn Ferrite." High Temperature Materials and Processes 35, no. 5 (May 1, 2016): 531–34. http://dx.doi.org/10.1515/htmp-2014-0223.

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AbstractCr-substituted Ni0.2Cu0.2Zn0.6Fe2–xCrxO4 ferrites (where x = 0–1.0) were prepared by solid-state reaction. The effects of Cr content on structural and magnetic properties were investigated. X-ray diffraction (XRD) revealed the formation of ferrite particles with cubic spinel structure. The lattice parameter and average crystallite sizes are much dependent on the chromium content and are found to decrease with its increasing. The initial permeability (μi) and saturation flux density (Bs) decrease with the increasing Cr content. In addition, without substituted ceramic samples possess lower quality factor (Q factor) than the NiCuZn ferrites with Cr substituted.

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Masala, Ombretta, Darin Hoffman, Nalini Sundaram, Katharine Page, Thomas Proffen, Gavin Lawes, and Ram Seshadri. "Preparation of magnetic spinel ferrite core/shell nanoparticles: Soft ferrites on hard ferrites and vice versa." Solid State Sciences 8, no. 9 (September 2006): 1015–22. http://dx.doi.org/10.1016/j.solidstatesciences.2006.04.014.

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Othéro de Brito, Vera Lúcia, Stéphanie Alá Cunha, Ana Paula Ribeiro Uchoas, Fabiana Faria de Araújo, Cristina Bormio Nunes, and Luis Antonio Genova. "Evaluation of the Sinterability of Copper-Substituted Ferrites by Means of Dilatometric Thermal Analysis." Materials Science Forum 805 (September 2014): 254–59. http://dx.doi.org/10.4028/www.scientific.net/msf.805.254.

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Cobalt and cobalt-manganese spinel ferrites have magnetostrictive properties suitable for application in magneto-electric and magneto-mechanical transducers. In this work, copper-substituted ferrites of these compositions were processed by means of the ceramic method and their sinterabilities were evaluated by dilatometric thermal analyses. The results obtained suggest that copper affects the solid-state reactions for the spinel formation and lowers the required sintering temperature for the ferrites. However, the densification obtained with sintering of the copper-substituted ferrites at 950oC for 6h was only 64%, which indicates that further adjustments on the processing route must be made in order to obtain higher densities.

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FU, X. L., Q. K. XING, Z. J. PENG, C. B. WANG, Z. Q. FU, L. H. QI, and H. Z. MIAO. "MICROSTRUCTURAL AND ELECTROMAGNETIC PROPERTIES OF Mn–Zn FERRITES WITH LOW MELTING-POINT NONMAGNETIC Sb3+ IONS." International Journal of Modern Physics B 27, no. 04 (December 20, 2012): 1350003. http://dx.doi.org/10.1142/s0217979213500033.

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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.

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41

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.

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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.

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42

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.

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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.

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Rafienia, Mohammad, Ashkan Bigham, and SeyedAli Hassanzadeh-Tabrizi. "Solvothermal synthesis of magnetic spinel ferrites." Journal of Medical Signals & Sensors 8, no. 2 (2018): 108. http://dx.doi.org/10.4103/jmss.jmss_49_17.

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Lukens, Wayne W., Nicola Magnani, Tolek Tyliszczak, Carolyn I. Pearce, and David K. Shuh. "Incorporation of Technetium into Spinel Ferrites." Environmental Science & Technology 50, no. 23 (November 22, 2016): 13160–68. http://dx.doi.org/10.1021/acs.est.6b04209.

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45

Rafienia, Mohammad, Ashkan Bigham, and SeyedAli Hassanzadeh-Tabrizi. "Solvothermal synthesis of magnetic spinel ferrites." Journal of Medical Signals and Sensors 8, no. 2 (2018): 108. http://dx.doi.org/10.4103/2228-7477.232087.

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46

Cruz-Franco, Berenice, Thomas Gaudisson, Souad Ammar, Ana Maria Bolarin-Miro, Felix Sanchez de Jesus, Frederic Mazaleyrat, Sophie Nowak, Gabriela Vazquez-Victorio, Raul Ortega-Zempoalteca, and Raul Valenzuela. "Magnetic Properties of Nanostructured Spinel Ferrites." IEEE Transactions on Magnetics 50, no. 4 (April 2014): 1–6. http://dx.doi.org/10.1109/tmag.2013.2283875.

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47

Graves, P. R., C. Johnston, and J. J. Campaniello. "Raman scattering in spinel structure ferrites." Materials Research Bulletin 23, no. 11 (November 1988): 1651–60. http://dx.doi.org/10.1016/0025-5408(88)90255-3.

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48

Thorat, Lankeshwar M., Digambar Y. Nadargi, Mohaseen S. Tamboli, Abdullah M. Al-Enizi, Rahul C. Kambale, Shoyebmohamad F. Shaikh, Shard S. Suryavanshi, Mohd Ubaidullah, Ayman Nafady, and Mohammed A. Al-Abdrabalnabia. "Co2+ Substituted Spinel MgCuZn Ferrimagnetic Oxide: A Highly Versatile Electromagnetic Material via a Facile Molten Salt Route." Nanomaterials 10, no. 12 (November 25, 2020): 2333. http://dx.doi.org/10.3390/nano10122333.

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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.

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Tsoncheva, Tanya, Radostina Ivanova, Nikolay Velinov, Daniela Kovacheva, Ivanka Spassova, Daniela Karashanova, and Nartzislav Petrov. "Design and Catalytic Behaviour of Hosted in Activated Carbon Foam CoxZn1−xFe2O4 Ferrites." Symmetry 13, no. 8 (August 20, 2021): 1532. http://dx.doi.org/10.3390/sym13081532.

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Carbon foams with different surface functionality and tailored texture characteristics were prepared from mixtures containing coal tar pitch and furfural in different proportions. The obtained materials were used as a host matrix for the preparation of zinc- and cobalt-mixed ferrite nanoparticles. The texture, morphology, phase composition, and the related redox and catalytic properties of the obtained composites were characterized by low-temperature nitrogen physisorption, XRD, SEM, HRTEM, FTIR, Mössbauer spectroscopy, TPR and catalytic decomposition of methanol to syngas. The impact of the carbon support on the formation of Co- and Zn-mixed ferrites was discussed in detail using KIT-6 silica-based modifications as reference samples. The catalytic behavior of the ferrites was considered in a complex relation to their composition, morphology, location in the porous matrix and metal ions distribution in the spinel sub-lattices. The higher amount of furfural in the carbon foam precursor promoted the formation of cobalt-rich, more accessible and highly active methanol decomposition to syngas spinel particles.

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Ulpe, Anna C., Katharina C. L. Bauerfeind, Luis I. Granone, Arsou Arimi, Lena Megatif, Ralf Dillert, Sven Warfsmann, et al. "Photoelectrochemistry of Ferrites: Theoretical Predictions vs. Experimental Results." Zeitschrift für Physikalische Chemie 234, no. 4 (April 28, 2020): 719–76. http://dx.doi.org/10.1515/zpch-2019-1449.

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AbstractThis paper gives an overview about recent theoretical and experimental work on electronic and optical properties of spinel ferrites MFe2O4. These compounds have come into focus of research due to their possible application as photocatalyst material for photoelectrochemical water splitting. The theoretical background of state-of-the-art quantum-chemical approaches applied for predicting electronic and optical band gaps, absolute band positions, optical absorption spectra, dielectric functions and Raman spectra, is briefly reviewed. Recent applications of first-principles methods on magnetic and electronic properties of ferrites with M = Mg and the first row of subgroup elements Sc to Zn are presented, where it is shown that the fundamental band gap is strongly dependent on the spin state and the degree of inversion of the spinel structure. The observed variation of electronic properties may serve as an explanation for the large scattering of experimental results. The exchange of M and Fe cations has also a pronounced effect on the Raman spectra of ferrites, which is analyzed at atomic scale from first principles. Calculated optical absorption spectra of ferrites are compared to experimental spectra. The electronic nature of the first excitations and the role of oxygen vacancies are discussed. For the calculation of absolute band positions, which have a significant impact on the photoelectrochemical activity of the ferrites, models of the most stable ferrite surfaces are developed that take into account their polar nature and the interaction with the solvent. Theoretically predicted valence and conduction band edges are compared to results from electrochemical measurements. The role of cation exchange on the surface electronic structure is investigated both theoretically and experimentally.

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Journal articles on the topic 'Ferrites spinel'

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