Dissertations / Theses on the topic 'Ion-Beam-Assisted Deposition'

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1986.
MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE.
Bibliography: leaves 75-76.
by Gordon M. Shedd.
M.S.

beta-FeSi2 has been shown to have a minimum direct band gap of 0.87 eV, which leads to the opportunity of Si based opto-electronics. One of the many applications that beta-FeSi2 has been linked with is solar cells. Its proposed suitability for solar cell applications originates from a large absorption coefficient above the fundamental edge (105 cm-1), predicted solar cell efficiencies as high as 23% and photoelectric properties with a quantum efficiency of 32%. Ion beam assisted deposition represent a technique that is suitable for producing low cost material over large areas, thus making it suitable for solar cell fabrication. The work reported here represents an in-depth optical characterisation of the effects of fabrication and post-fabrication processing on ion beam assisted deposited FeSi layers on Si substrates. Two different sets of substrates have been investigated; the first were deposited with layers of Fe and Si in the ratios between (40%:60%) and (29%:71%), and the second were deposited in stoichiometric ratios (1:2). A range of post-fabrication processes have been investigated, these have included studying the effects of annealing time (10 minutes to 18 hours) and temperature (100°C to 900°C) on the band gap and defects underneath the fundamental absorption edge. A study of the effect of annealing regime on the measurement temperature dependency of the band gap was also completed. The results have shown that annealing temperature has a stronger effect on the band gap rather than annealing time, while both affect the absorption underneath the fundamental edge. Optical evidence for the formation of beta-FeSi2 was found for annealing temperatures as low as 425°C. Increasing the annealing temperature/time also results in structural changes in the material, which are dependent on the as-deposited composition of the FeSi layer. beta-FeSi2/Si(n-type) solar cell devices have been fabricating, showing rectifying I-V characteristics, and a photo-voltage spectral response that indicated two distinct regions; 0.72 eV to 1.1 eV and 1.1 eV and above.

This thesis is divided into three main parts dealing with ion beam assisted deposition. In the first part there is a brief description of the IBAD chamber at Institute of Physical Engineering of BUT. There is also a detailed description of control of the IBAD apparatus during deposition. Next part deals with measuring of deposition rates of ion sputtering in order to refine deposition of thin layers. Last part deals with planned and already finished changes that should improve quality and speed of thin layers deposition. Changes include the option of covering the substrate holder, change of the entry flange, design of new insertion chamber with multifunctional substrate holder and the option to control the deposition by computer.

Este trabalho tem por objetivo a caracterização de filmes finos de óxido de alumínio produzidos por deposição assistida por feixe de íons Ar+. Tal caracterização consiste em estabelecer a relação entre os parâmetros de produção (energia do feixe e uxo relativo de Ar), a composição e a estrutura dos lmes. Para tanto, utiliza-se técnicas de microscopia de força atômica, difração de raios-x, reetividade de raios-x e análise por feixe iônico. Resultados mostram que amostras produzidas à temperatura ambiente e à 450 oC são amorfas independentemente da energia do feixe iônico. Filmes formados com assistência de feixe possuem qualidade superior àqueles formados por deposição física de vapor. O bombardeamento de íons Ar+ mostra-se capaz de controlar a concentração de hidrogênio, a estequiometria, a rugosidade, o tamanho dos grãos e a densidade dos lmes nos. Amostras com excelente qualidade baixa rugosidade, estequiometria próxima da ideal e boa densidade foram produzidas utilizando íons com energia dentre 300 eV e 600 eV.
The scope of this work is the characterization of aluminum oxide thin films produced by Ar+ ion beam assisted deposition. This characterization consists in establishing the relationship between production parameters (ion beam energy and argon relative ux), structure and composition of these lms. In order to undertake this task, the following techniques were used: atomic force microscopy, x-ray diraction, x-ray reectivity and ion beam analysis. Results show that samples produced at room temperature and at 450 oC are amorphous regardless the ion beam energy. Films grown under ion assistance have better characteristics than the ones deposited by physical vapor deposition. The ion beam bombardment is capable of controlling hydrogen concentration, stoichiometry, roughness, grain size and density of alumina samples. High quality lms at surface and increased density lms with near ideal stoichiometry were produced with 300 eV and 600 eV ion beam energy.

Orientador: Fernando Alvarez
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
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Resumo: Nesta tese são apresentados os efeitos nas propriedades estruturais, eletrônicas e de emissão eletrônica por efeito de campo elétrico induzidos pela incorporação de nitrogênio em nanoestruturas de carbono. As nanoestruturas de carbono contendo nitrogênio foram preparadas por pulverização catódica (sputtering) de um alvo de grafite assistido, ou não, por um feixe iônico. A técnica permite atuar sobre os parâmetros de deposição induzindo mudanças nas propriedades estruturais, eletrônicas e de emissão eletrônica por efeito de campo elétrico. O papel do hélio na formação de nanoes-truturas de carbono contendo nitrogênio foi também explorado, mostrando que o gás nobre promove maior incorporação de nitrogênio. Isto é provavelmente devido à relativa alta condutividade térmica que apresenta o hélio, propriedade que modifica a cinética do crescimento das nanoestruturas. O estudo realizado permitiu entender o mecanismo de formação das nanoestruturas, mostrando que primeiramente o carbono alcança as partículas de Ni por difusão até a saturação do metal, iniciando a formação das camadas grafíticas sobre a partícula de Ni, camadas que foram observadas por microscopia eletrônica de transmissão de alta resolução. O estudo mostra, também, que os parâmetros importantes que controlam a incorporação de nitrogênio no material são a pressão parcial de nitrogênio na câmara de deposição, assim como a energia do feixe de íons assistindo a deposição.Foram estudadas três séries de amostras preparadas em atmosferas controladas. Na primeira série foi utilizado um feixe de íons de nitrogênio como feixe de assistência, e na segunda, uma mistura composta por duas espécies iônicas, íons de nitrogênio e hidrogênio. Com o auxilio da espectroscopia de elétrons fotoemitidos por raios-X observou-se a incorporação de nitrogênio nos filmes. A microscopia de força atômica revelou a presença de estruturas do tipo domo, distribuídas de maneira uniforme na superfície das amostras, apresentando uma densidade média de ~3×10 9 domos/cm 2as da primeira série, e ~1.4×10 9 domos/cm 2as da segunda série. Tanto a distribuição como a forma seguem o padrão estabelecido pelos precursores utilizados na preparação das nanoestruturas, i.e., ilhas de níquel que agem ao mesmo tempo como catalisadores e como suporte para as nanoestruturas. Na terceira série, as nanoestruturas foram crescidas sobre um filme de nitreto de titânio, depositado sobre substratos de Si, pulverizando um alvo de grafite em atmosferas de nitrogênio e hélio-nitrogênio. A densidade dos domos encontrada para esta série foi de ~5.3×10 10 domos/cm 2 . Os espectros Raman das três séries apresentam as bandas G e D, o que indica a presença estruturas grafíticas com distorções representadas pela banda D. A incorporação de nitrogênio ocasiona o alargamento da banda G e aumento da razão das intensidades das bandas D e G, respectivamente, indicando uma redução da ordem estrutural com a incorporação de Nitrogênio. Finalmente, para as três séries de amostras, fez-se também um estudo das propriedades de emissão eletrônica por efeito de campo elétrico. A emissão é predominantemente por tunelamento quântico (as curvas de densidade de corrente vs campo elétrico seguem o modelo de Fowler-Nordheim) e dependem da concentração de nitrogênio assim como do processo usado na preparação das amostras
Abstract: The subject of this thesis is establishing a link among the synthesis, structures, and field emission properties for nanostructured carbon materials containing nitrogen. The materials were prepared by ion beam assisted deposition and ion beam sputtering. The carbon material was obtained sputtering an ultra pure graphite target by an argon ion beam. The method allows controlling the deposition parameters to induce changes in the structural, electronic, and field emission properties. Also, the role of helium on the carbon containing nitrogen nanostructures was investigated. The remarkable thermal conductance of He modifying the growing kinetics was also studied. An important goal of the work was to elucidate the mechanism of the nanostructures formation. It was found that, at first, the carbon atoms reach the Ni particles saturating the metal particle, and then, the formation of stacked graphene starts on the metal particles. The graphene layers were observed by high resolution transmission electron microscopy. The results show that mainly two parameters control the nitrogen incorporation, namely, the deposition chamber nitrogen partial pressure and the energy of the nitrogen ion beam assisting the growth. Three sample series prepared in controlled atmospheres were studied. The first series was prepared assisting the growth with a nitrogen ion beam and, the second series by a nitrogen-hydrogen ion beam. The third sample series were prepared by ion beam sputtering on silicon substrate by sequentially depositing titanium nitride thin film, nanometric nickel particles and carbon. The carbon containing nitrogen nanostructures were grown in nitrogen and helium-nitrogen atmospheres. X-ray photoelectron spectroscopy analysis indicates nitrogen incorporation and it depends predominantly on the ion beam energy or on the nitrogen partial pressure. Atomic force microscopy reveals dome-like structures uniformly distributed on the surface of the samples, with ~3×10 9 domes/cm 2 for the first series, ~1.4×10 9 domes/cm 2 for the second, and ~5.3×10 10 domes/cm 2 for the third. Both distribution and shape follow the Ni island pattern, i.e. the Ni islandsact both as a catalytic and uphold. The three samples series were also analyzed by Raman spectros-copy, showing a defined G bands around 1593 cm -1 indicating the presence of graphitic structures. Also, are observed D bands indicating structural disorder. The disorder increases with the augment of the nitrogen content, as is shown by the augment of the D and G intensities ratio. Finally, the field emission properties of the three series were studied and the electron emission depends on the growing conditions in general, and on the nitrogen content in particular. The results show that the emission is predominantly by quantum tunneling and the current density vs. electric field curves follow the Fowler-Nordheim model
Doutorado
Física
Doutor em Ciências

Les filtres optiques à grand nombre de couches minces constituent un élément clé de la performance et de l’innovation des systèmes optiques. Les revêtements de surface dédiés à l’optique sont des vecteurs de recherche dans tous les secteurs industriels associés à l’optique. La conception et la réalisation des filtres optiques multicouches à grand nombre de couches minces opérant dans le moyen infrarouge de 2 µm à 15 µm sont la problématique de recherche de ces travaux de thèse. Dans cette thèse, l’accent a été mis sur l’étude, le déploiement, l’amélioration et l’optimisation des procédures de dépôt du Sulfure de Zinc (ZnS) et de Germanium (Ge). L’optimisation des constantes optiques du Germanium en fonction des paramètres de dépôt par la méthode des plans d’expériences est présentée et discutée. Un plan d'expérience a été utilisé pour étudier et optimiser les conditions de dépôt du Germanium. Ce plan d'expérience traitait 4 paramètres de dépôt : la vitesse de dépôt, le vide avant dépôt, la pression de dépôt et l'assistance ionique (IAD) Les résultats extraits du plan d’expérience comprennent les effets importants de la vitesse de dépôt, de l’assistance ionique de compactage et de leurs interactions, l’effet dissipatif du vide avant dépôt et de la pression de dépôt dans l'enceinte de dépôt sur l’énergie de croissance de la couche mince, et l’obtention d’un ensemble de conditions de dépôt optimisées pour réaliser des couches minces de Germanium avec un indice de réfraction le plus haut possible et un coefficient d’extinction le plus bas possible. Les mises en empilement des matériaux nous ont permis de réaliser plusieurs types de filtres optiques, des revêtements antireflets de 2 µm à 14 µm composés de 2 à 11 couches minces, un miroir à 10,6 µm en 9 couches minces ou bien un filtre dichroïque composé d'un miroir de 2 µm à 5 µm et d'un revêtement antireflet de 8 µm à 14 µm constitué de 29 couches minces. Nous avons pu étudier la fiabilité et la robustesse des couches minces des matériaux améliorés et optimisés
Optical filters with a large number of thin films are key elements in the performance and innovation of optical systems. The surface coatings dedicated to optics are vectors of research in all the industrial sectors associated with optics. The design and fabrication of multi-layer optical filters with large number of thin layers with applications in the mid-Infrared spectral range (from 2 µm to 15 µm) are the research problem of this thesis work. In this thesis, the focus was placed on the study, deployment, improvement and optimization of the deposition procedures of Zinc Sulphide (ZnS) and Germanium (Ge). The optimization of the optical constants of Germanium according to the deposition parameters by the design of experiments method is presented and discussed. A design of experiments (DOE) was used to study and optimize Germanium’s deposition conditions, the experiment plan dealt with 4 deposition parameters: deposition speed, pre-deposition vacuum, deposition pressure and ion assisted support (IAD). The results extracted from the DOE include the significant effects of deposition rate, IAD and their interactions, the dissipative effect of pre-deposition vacuum and deposition pressure in the deposition chamber on the growth energy of the thin layer, and a set of deposition conditions optimized to achieve thin layers of Germanium with the highest possible refractive index and extinction coefficient. The stacking of Ge and ZnS thin layers enabled us to fabricate several types of optical filters namely an antireflective coatings from 2 µm to 14 µm composed of 2 to 11 thin layers, a 9 thin-layers mirror at 10,6 µm or a dichroic filter consisting of a 2 µm to 5 µm mirror and an 8 µm to 14 µm antireflective coating consisting of 29 thin-film. Furthermore, we were able to study the reliability and robustness of the thin layers of improved and optimized materials

碩士
國立中山大學
光電工程研究所
94
Due to the fast expansion and development in the optical communication industry, the demand for the film quality has correspondingly increased. Ion beam sputter deposition (IBSD) achieves the lowest loss, but low throughput. In our Lab., E-beam system was used for CaO, MgO and Cr2O3 evaporation on the circumference of the Cr:YAG crystal fiber. Although the substrate was heated to around 275oC, the thin film didn’t achieve low loss and high laser-induced damage threshold film. Adding ion-beam assisted deposition (IAD) system to enhance the thin film energy and packing density is the main theme of this thesis. The thesis mainly focuses on the characteristics of TiO2 and SiO2 thin film based on E-beam with IAD system. Spectrometer analyzer and Macleod software were used to calculate the refractive index and extinction coefficient. ESCA (electron spectroscopy for chemical analyzer) was adopt to measure the thin film composition of Ti, Si, O. SEM (scanning electron microscope) was used to observe the thin film quality. Low loss and high laser-induced damage threshold thin film are the goal of the present research. With optimized parameters, the refractive index of TiO2 film was achieved to be 2.51 at 500 nm, and the extinction coefficient was less than 2x10-4. The refractive index of SiO2 film can be achieved to be 1.466 at 500 nm, and the extinction coefficient was less than 1x10-4. An HR (R>99.83%) coating at 1233 nm was successfully demonstrated by the IAD deposition system.

碩士
國立中央大學
光電科學研究所
97
Thermal boat evaporation was employed to prepare LaF3 single-layer coatings for UV applications. Optical properties and microstructure, including transmittance, index refraction, extinction coefficient, and surface properties, were measured by spectrophotometer, ellipsometric, SEM, and AFM. With pulse mode IAD, we can make lanthanum fluoride thin film to have higher packing density and decrease annoying absorption at wavelength rage190 to 350nm caused by constant IAD. With optimized parameters, refraction index of lanthanum fluoride thin film was raised from 1.68 to 1.7 at 190nm, extinchomogeneity of tion coefficient was reduced 14%, and surface roughness was reduced 1/3. Since thin film’s quality was improved to reduce the inhomogeneous phenomenon, the transmittances of halfwave optical thickness go back to the transmittance of substrate.

碩士
國立中央大學
光電科學研究所
96
TiO2 has diverse functional application in solar cell, sterilization, degradation of organic pollutants and self-cleaning, however, the photocatalytic activities of titanium dioxide can effectively work only under ultraviolet (UV) light irradiation. In the hydrophilicity experiment, we get better photocatalytic activities films in using ion assisted deposition under anode voltage 40V than without using ion assisted deposition, after the UV light treatment 5 minutes, the contact angle was less than 10 degree. Besides, in the N2 ion assisted deposition experiment, to investigate N state in TiO2-xNx, and found that, the XPS peak at 396eV of N binding signal is clear observed .After the visible light treatment for one hour, the contact angle was 20 degree, and after the visible light treatment for two hours, the contact angle was less than 10 degree.

碩士
國立中央大學
光電科學研究所
95
The deposition of magnesium fluoride optical thin film by using thermal boat evaporation with pulse ion-assisted deposition (IAD) for UV application was investigated in this thesis. Due to the ion beam assistance, the optical properties and micro-structural properties of the magnesium fluorides thin films, including refractive index, surface roughness were significantly improved which are required in laser material processing and semiconductor lithography.

碩士
國立雲林科技大學
電子工程系
105
Transparent conductive oxide(TCO) with high transmittance and excellent conductivity, It has been widely used as photovoltaic components. Because of the cost of materials is lower than the commonly used indium tin oxide(ITO), niobium doped titanium dioxide(TNO) is a promising transparent conducting oxide material In this study, transparent conductive Nb-doped TiO2 (TNO) thin films were deposited onto glass substrate, using the electron beam gun evaporation method. There are two kinds of penetration way, one is slug type and the other is powder type. Nb-doped TiO2 thin films with different doping concentration and different annealing temperature were researched.The TNO thin films were measured thickness by α-step. Structural and composition were analyzed by energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD). And then measured by UV-Visible spectrometer and Hall effect measurement system to observed transmittance and electrical properties. The results show the best Nb-doping concentration is 10wt% of Nb2O5, the ratio of atom of Ti and Nb, Nb/(Ti+Nb), is 9.13at%. After annealed in 400℃, the structural changed into anatase from amorphous. The average transmittance is 70% in visible region. The lowest resistivity is 2.33×10-3Ω-cm.

碩士
國立交通大學
電子物理系
86
Znse films were grown on quartzs and GaAs (100) substrates by cw CO2 laser with ion beam-assisted deposition. The films grown on quartz substrates were the zinc-blende polycrystalline structure with a strong preferred [111] orientation, even deposited on room teperature substrates.Without ion beam assistance, the film grown at a substrate temperature 150℃, a growth rate 6.4 A/sec had the best properties which the refractive index was 2, 5218, the extinction coefficient was 0.0016 at 700 nm and the peel strength was 11.44 mN. With ion beam assistance, the film grown at a ion beam voltage 200V, a ion beam current 15 mA was the best one whose refractive index was 2.536 close to single crystal ZnSe bulk 2.6540, extinction coefficient was 0.0010 and peel strength was 16.9 mN. From Raman measurements, the stress between the ZnSe film and the quartz substrate was 1.27×1013 dyn cm-2 We found that the properties of polycrystalline ZnSe films prepared by the system we used were better then those by the traditional thermal and electron beam evaporation. 　　When the substrate temperature was above 200℃, the ZnSe film grown on a GaAs (100) substrate became a single crystal. By the way, we found that the low energy ion beam could remove the oxide covering over the GaAs substrate surface. Raman measurements showed that the stress between the film grown at 400℃ and the Ga As (100) substrate was smallest and the film transmittance to 488 nm laser beam was highest. According to spatial correlation model of Raman scattering, the coherence length (L=16.5 nm) of the film grown at 350℃ was longest. PL of the film grown at 400℃ was gotten. The low temperature (T=20K) PL showed that the energy of the donor-bound exciton (I2) transition was 2.795 eV and the FWHM was 7.6 meV. From PL measurements at different temperatures, the linear temperature coefficient of I2 was-4.3×10-4 eV K-1 and the activation energy was 25 meV.

碩士
明志科技大學
材料工程系碩士班
103
This study included two parts. In the first part, Ga-doped zinc oxide (GZO) and Cu2O thin films were deposited on glass substrates by Ion-Beam-Assisted Deposition (IBAD). The effects of ion beam discharge current and O2/Ar ratio on the structural, optical, and electrical properties of these films were investigated. The optical emission spectra of the applied ion beam were examined using an optical emission spectrometer (OES). The correlation of optical emission and films’ properties was studied. After the analysis of opto-electrical behaviors over the deposited films, a GZO and a Cu2O films were selected to make a PN junction on the glass substrate. For this device, Ag was chosen as the electrode material. In the second part, Ga2O3 thin films with various thickness (5 ~ 20 nm), also deposited by IBAD, were inserted between GZO and Cu2O layers, and the I-V curves were measured and analyzed. The inserted Ga2O3 layer was thought to reduce the defect density at the interface, and, therefore, improve the efficiency. In sum, it is found that the discharge current and O2/Ar ratio had significant effects on these films’ structural, optical, and electrical properties (except Ga2O3). The optimum conditions was found when discharge current = 0.2~0.35 A, and O2/Ar = 1/3.

碩士
國立東華大學
材料科學與工程學系
92
Abstract The aim of the study focus on the preparation, nano-structure, analysis and photocatalytic behaviors of nitrogen and carbon doped TiO2 thin films. TiO2-xNx and TiO2-xCx films were prepared with ion gun assisted electron beam evaporation system using 99.9 % rutile TiO2 as a source material. The processing parameters, including nitrogen flow rate, oxygen flow rate, carbon dioxide flow rate, substrate temperature, thickness, beam current and beam voltage, are modulated to obtain the best photocatalytic properties of the films. XRD, Raman and XPS were used to detect the film structure crystallinity and surface composition. SEM and AFM were used to observe the surface morphology and roughness. The ultraviolet-visible (UV-vis.) spectrophotometer was used to analyse the absorption spectra of the films. The photocatalytic related properties under visible light were characterized by the water-contact angle measurement, oxidation of methylene blue in aqueous solution, and reduction of Ag+ to Ag in AgNO3 aqueous solution. The relations among the processing parameter, structure and photocatalytic property are discussed in the study. The critical thickness of the TiO2-xNx film to obtain the best superhydrophilic and photocatalytic properties is about 1.2μm. The TiO2-xNx film has the absorption edge at 535 nm in the UV-Vis spectrum, this result is better than literature report (absorption edge < 500 nm). It was found that the TiO2-xNx films with a much higher roughness exhibited better hydrophilic. Variations in thickness and crystallinity in the TiO2-xNx films made their photocatalytic properties different. It was found that the TiO2-xNx films with well-crystallized anatase phase exhibited the best photocatalytic performance. The well-crystallized anatase TiO2-xNx film, deposited with oxygen flow rate of 4 sccm, 1200 nm of thickness, 10 mA of beam current and 2 Å / sec evaporation-rate at 300oC, exhibited the lowest contact-angle of 3° and the best photocatalytic activity on the degradation of methylene-blue with a rate-constant (k) about 0.293 hr-1 and the best reduction rate of Ag+ to Ag under visible light illumination. The TiO2-xCx films maintain the structure of anatase TiO2, deposited at various carbon dioxide flow rate. The result indicates the absorption edges of the resulting films red-shift gradually to 435 nm (literature reported that TiO2-xCx films show two optical absorption thresholds at 535 and 440 nm in the visible range) and the water contact-angles reduce to about 3° upon exposure to visible light. Similarly, the films deposited with 6.21 sccm CO2 in the ion gun exhibit the best photocatalytic activity with the rate-constant (k) about 0.057 hr-1. However, the photocatalytic activity of TiO2-xCx films compare poorly with TiO2-xNx films. Keywords: photocatalyst, hydrophilicity, absorption edge, titanium dioxide.

Thesis (M.S.)--University of Wisconsin--Madison, 1999.
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碩士
輔仁大學
物理學系
99
Carbon/nitrogen-doped titanium oxide films were prepared by ion-beam assisted RF magnetron sputtering deposition. We want to extend the absorption edge of titanium oxide from UV region to visible light region , enhance the function of C/N-doped TiO2 films. 　　The anatase of carbon/nitrogen-doped titanium oxide were prepared at substrate temperature 500℃ in plasmas of CO2 and N2 mixture .The prepared samples were characterized by a series of analytical methods including UV-Vis spectrophotometer , atomic force microscope，X-ray diffraction , X-ray photoelectron spectroscopy and Methylene blue degradation , which to measure the optical properties and band gap , morphology , crystallinity ,bonding and photocatalyst. 　　In the XPS analysis, there are β-N bonding and C-N bonding in the film , it affects narrowing the band gap of titanium oxide. The XRD analysis found the crystallinity will become weak in the N2 process, and in the CO2 process, the anatase was induced to rutile. In the decompose methylene blue experiment , the C/N-TiO2 film with the IAD exhibits the best visible light(460 nm) photocatalytic activity . The band gap of C/N-TiO2 film was narrowing from 3.2eVto 2.69eV. It was demonstrated in this study that the process is useful to reduce the band gap and enhance the photocatalytic property.

To facilitate ferroelectric-based actuator integration with silicon electronics fabrication technology, we have developed a route to produce biaxially textured ferroelectrics on amorphous layers by using biaxially textured MgO templates.

Using a kinematical electron scattering model, we show that the RHEED pattern from a biaxially textured polycrystalline film can be calculated from an analytic solution to the electron scattering probability. We found that diffraction spot shapes are sensitive to out-of-plane orientation distributions and in-plane RHEED rocking curves are sensitive to the in-plane orientation distribution. Using information from the simulation, a RHEED-based experimental technique was developed for in situ measurement of MgO biaxial texture. The accuracy of this technique was confirmed by comparing RHEED measurements of in-plane and out-of-plane orientation distribution with synchrotron x-ray rocking curve measurements.

Biaxially textured MgO was grown on amorphous Si3N4 by ion beam-assisted deposition (IBAD). MgO was e-beam evaporated onto the amorphous substrate with a simultaneous 750-1200 eV Ar⁺ ion bombardment at 45° from normal incidence. We observed a previously unseen, dramatic texture evolution in IBAD MgO using transmission electron microscopy (TEM) and RHEED-based quantitative texture measurements of MgO. The first layers of IBAD MgO are diffraction amorphous until the film is about 3.5 nm thick. During the next 1 nm of additional growth, we observed rapid biaxial texture evolution. RHEED and TEM studies indicate that biaxially textured MgO film results from a solid phase crystallization of biaxially textured MgO crystals in an amorphous matrix.

Biaxially textured perovskite ferroelectrics were grown on biaxially textured MgO templates using sol-gel, metallorganic chemical vapor deposition (MOCVD), and molecular beam epitaxy (MBE). Through RHEED-based biaxial texture analysis we observed that the heteroepitaxial ferroelectric in-plane orientation distribution, deposited using ex situ techniques (not performed in the same high vacuum growth environment where the MgO was deposited), narrowed significantly with respect to the in-plane orientation distribution of its MgO template (from 11° to 6° FWHM). Evidence from cross section TEM and RHEED suggest that atmospheric moisture degrades the crystallinity of highly defective, misaligned MgO grains and that heteroepitaxially grown ferroelectrics preferentially nucleate on well-aligned grains and over grow misaligned regions of MgO.

The aim of this thesis is a systematic study of physical properties of magnetic multilayered nanostructures. Namely it include multilayered spin valves NiFe/Cu/Co with magnetic anisotropy iduced by magnetic field applied during the deposition. Induced magnetic anisotropy influences exchange interactions between magnetic layers and so it gives the possibility to control magnetic properties of nanolayers. This is important for applications in MRAM, magnetoresistive read heads and spin-transfer-torque devices. Magnetooptic spectroscopy and Kerr effect hysteresis loop measurement were used as effective probe techniques. Secondly we examinated Ar3+ rf sputtering influence on multilayer interface quality level. We found out, that Ar3+ irradiation during deposition process has a possitive effect on interface quality.