Orientador: Eudes Borges de Araújo / Banca: Rafael Zadorosny / Banca: Jesiel Freitas Carvalho / Resumo: O titanato zirconato de chumbo dopado com lantânio, dado convencionalmente pela fórmula estequiométrica Pb1− x Lax ( Zry ; Ti1− y ) 1− x / 4 O3 , com x = 0,09 e y = 0,65, também conhecido como PLZT 9/65/35, é um importante sistema ferroelétrico relaxor devido as suas propriedades dielétricas, elétricas e eletroóticas. Sendo um ferroelétrico, exibe, também, propriedades tais como piezo e piroeletricidade, dependendo apenas das proporções em que são preparados. Logo, esse sistema é bastante interessante para uma gama de aplicações tecnológicas. Na forma de filmes finos, a composição PLZT 9/65/35 tem sido amplamente estudada e preparada pelos mais diversos métodos. Neste trabalho propõe-se a síntese de filmes finos ferroelétricos da composição PLZT 9/65/35 pelo método dos precursores óxidos, a fim de se compreender a dinâmica dos processos de cristalização e, também, avaliar suas propriedades físicas, como permissividade elétrica e histerese ferroelétrica. A intenção, assim, é colaborar com as informações presentes na literatura sobre as propriedades de filmes finos de PLZT 9/65/35 / Abstract: The lead zirconate titanate doped with lanthanum, conventionally given by stoichiometric formula Pb1− x Lax ( Zry ; Ti1− y ) 1− x / 4 O3 , with x=0,09 and y=0,65, also known as PLZT 9/65/35, is an important relaxor ferroelectric system due to its dielectric, electrical and electrooptical properties. Being a ferroelectric material exhibits also properties such as piezo- and piroelectricity, depending upon the extent to which they are prepared. Therefore, this system is very interesting for a range of technological applications. In the thin films format, the composition PLZT 9/65/35 has been widely studied and prepared by several methods. In this project it is proposed the synthesis of thin films of such material by the oxide precursor method in order to understand the dynamics of crystallization process and also to evaluate their physical properties like electrical permittivity and ferroelectric hysteresis. The intention, thus, is collaborate with the information presented in the literature about the properties of PLZT 9/65/35 thin films / Mestre

No description available.

Neste trabalho, apresentamos o estudo magnético e magneto-óptico de filmes de R-Co e bicamada Y-Co/R-Co, R=Gd, Tb. Nesses filmes, três tipos de magnetismo são observados: ferromagnetismo (Y-CO), ferrimagnetismo (GdCo), e sperimagnetismo (Tb-Co). As amostras foram depositadas por DC magnetron sputtering sobre substrato de vidro e protegidas da oxidação por camadas de 30nm de espessura de Sl IND.3 N IND.4. A caracterização magnética das amostras foi feita com a utilização dos magnetômetros SQUID, MAVe MEK-bt. Uma grande parede de domínios, localizada na interface da bicamada amorfa YCo IND.2/GdCo IND.2 é formada durante uma transição ferri-ferromagnética macroscópica. O modelo para analisar a parede de domínios é baseado nas energias Zeeman, anisotropia e troca. Como resultado, nós obtivemos três equações interdependentes, relacionando a espessura da parede de domínios , a posição relativa da parede e a constante de troca A, para os pares atômicos Co-Co. Nesta tese, apresentamos a dependência térmica de , e A. O modelo foi aperfeiçoado para levar em conta a forma não usual da parede de domínios presente na interface da bicamada. A parede de domínios ocupa ~64% do volume da bicamada e está localizada, em sua maior parte (~60%),na camada Y-Co. A constante de troca A apresentou um decréscimo monotônico, com os valores variando de ~3.1xl0 POT.-7 erg/cm a 25K para ~2.0xl0 POT.-7 erg/cm à temperatura ambiente. O Gd foi substituído por Tb e o estudo da parede de domínios na bicamada amorfa YCo2/TbCo2 , é apresentado. A principal diferença entre os filmes de Gd-Co e de Th-Co é o tipo de magnetismo que eles apresentam: o primeiro é ferrimagnético e o segundo é sperimagnético. Como consequência, o filme de Tb-Co apresenta um campo de anisotropia multo maior que o filme de Gd-Co, à temperatura ambiente. O efeito da alta anisotropia sobre a bicamada é uma parede de domínios quase que totalmente localizada na camada Y-Co. Este comportamento foi usado para determinar a dependência de com o campo magnético aplicado, e o valor da constante de troca A para as diferentes temperaturas. O valor de A variou de 1.8xl0 POT.-7 erg/cm a 150K para 1.4xl0 POT.-7 erg/cm a 300K e, para todas as temperaturas, decresceu de ~100nm, no campo de transição (Ht), para ~20nm para lkOe. Para aumentar o entendimento sobre as bicamadas à base de Gd e Tb, a dependência térmica da magnetização de saturação de filmes de R-Co (R=Gd, Tb) foi simulada com a teoria de campo médio. Nós fizemos também o estudo introdutório de filmes ternários. As caracterizações magnética e magneto-óptica dos filmes de R-FeCo (R=Gd, Tb) , e da bicamada de Gd-FeCo/Tb-FeCo revelaram anisotropia planar e perpendicular nos filmes à base de Gd e Tb, respetivamente. / In this work we present the magnetic and magneto-optical study of thin films of R-Co and Y-Co/R-Co bilayer, R=Gd, Tb. Three different kínds of magnetism are found in these films: ferromagnetism (Y-Co), ferrimagnetism (Gd-Co) and sperímagnetísm (Tb-Co). The samples were deposíted by DC magnetron sputteríng on glass substrate, and were protected from oxídatíon by 30nm thick Sí3N4, layers. Magnetic characterization of the samples was done using SQUlD, VSM and transverse magneto-optícal Kerr effect (TMOKE) magnetometers. A large doma in wall (DW), localízed at the YCo2/ Gd Co2, amorphous bilayer interface, is formed duríng a macrosropic ferri-ferromagnetíc transitíon. A model to analyze the DW ís based on Zeeman, anísotropy and exchange energies. As a result, we obtained three interdependent equations, relatíng the DW thickness , the relative position of the wall , and the exchange constant A. In this PhD thesis we present the temperature dependence of , and A. The model was ímproved to account for the unusual DW present at the bílayer interface. About 60% of the DW was inside the Y-CO layer, and the DW was found to be quite large, occupying ~64% of the volume of the bilayer. The exchange constant A presents a monotonically decreasing value, ranging from ~3.1 xl0-7 erg/cm at 25K to ~2.0 Xl0-7 erg/cm at room temperature. Gd was replaced by Tb and a study of the DW in amorphous YCo2/TbCo2, bilayer is presented. The main difference between Gd-Co and Tb-Co films is the kind of magnetism they present, the first is ferrimagnetic and the second is sperimagnetíc. As a consequence, the Tb based film shows a much higher anisotropy field than the Gd-Co film, at room temperature. The high Tb-Co anisotropy effect on the bílayer is a DW almost totally localized in the Y-Co layer. This behavior was used to determine the dependence on the magnetic field and the exchange constant A for different temperatures. A ranged from 1.8xl0-7 erg/cm at 150K to 1.4xl0-7 erg/cm at 300K and, for all temperatures, decreases from ~l00nm, at the transition field (Ht), to ~20nm at lkOe. In order to increase the understanding of the Gd and Tb based bilayers, the temperature dependence of the saturation magnetization of R-Co (R=Gd,Tb) films was simulated by the mean field theory. The values of exchange integrais JR-Co between R and Co atoms are in agreement to the literature. We also studied some ternary tilms, but in less detail. The magnetic and magneto-optical characterization of R-FeCo (R=Gd, Tb) films and GdFeCo/Tb-FeCo bilayer revealed an in-plane and perpendicular anisotropy in Gd and in Tb based fiims, respectively.

Os filmes moleculares constituídos por complexos polipiridínicos de rutênio, clusters trigonais de acetato de rutênio e porfirinas polimetaladas, tem sido investigados de forma sistemática, proporcionando uma ampla variedade de interfaces funcionais, para uso em dispositivos eletrônicos, sensores, células electrocatalíticas e de fotoconversão de energia. Tais filmes tem sido gerados por meio de métodos conhecidos como dip coating, drop casting, e deposição química/eletroquímica, apresentando aspectos morfológicos extremamente ricos, os quais foram investigados nesta tese, por meio de microscopia de varredura de sonda. Estudos de microscopia de força atômica foram dirigidos para os filmes moleculares gerados por dip coating. As imagens foram analisadas com bons resultados através do Programa da Gwyddion, permitindo a avaliação dos parâmetros de rugosidade envolvidos nas formas e distribuição dos grãos superficiais. Os filmes obtidos por drop casting foram investigados por meio da microscopia de força atômica, MACMode, apresentando uma grande variedade morfológica, associada principalmente com o processo de dewetting, sob a influência de interações moleculares específicas. A eletropolimerização dos complexos foi monitorada por meio de AFM condutivo, permitindo sondar as características condutoras dos filmes poliméricos. Filmes de DNA e nanopartículas magnéticas ancoradas sobre superfície de ouro foram investigados através de AFM MACMode, e AFM magnético, respectivamente. Finalmente, uma nova abordagem de sondas ultrassensitivas, foi explorada através da imobilização de nanopartículas magnéticas sobre MACLevers, ampliando os limites de detecção gravimétrica até sub-picograma. / Molecular films constituted by ruthenium polypyridine complexes, triangular ruthenium acetate clusters, and polymetallated porphyrins have been systematically investigated, providing a wide range of functional interfaces for electronic devices, sensors, photoconversion and electrocatalytical cells. Such films have been generated by dip coating, drop casting and electrochemical deposition, displaying very rich morphological aspects, which have been investigated by means of scanning probe microscopy. AFM studies have been carried out for the molecular films generated by dip coating. The images were successfully analysed using the Gwyddion software, allowing the evaluation of the rugosity parameters determining the grain shapes and distribution over the films. The films obtained by drop casting have been investigated by means of MACMode SFM, exhiting a wide variety of morphologies, mainly associated with the dewetting of the samples, under the influence of specific molecular interactions. Electropolymerization of molecular complexes have been monitored by SFM techniques, including the electroconducting mode to probe the conductivity of the polymeric films. Gold anchored films of DNA and magnetic nanoparticles have also been successfully investigated by MACMode SFM and magnetic SFM techniques, respectively. Finally, a new approach for ultra-sensitive probes, based on the immobilization of magnetic nanoparticles onto the MACLevers has been devised, allowing the detection of sub-picogram amounts of analytes

>Magister Scientiae - MSc / This project focuses on the simple, fast and highly sensitive adsorptive stripping voltammetry detection of Nickel and Cobalt complexed with DMG and Nioxime respectively at a Reduced Graphene Oxide modified pencil graphite electrode in water samples. This research as well demonstrates a novel electrochemically reduced graphene oxide (ERGO)/mercury film (MF) nanocomposite modified PGE, prepared through successive electrochemical reduction of graphene oxide (GO) sheets and in-situ plated mercury film. The GO and graphene were characterized using FT-IR, HR-SEM, HR-TEM, XRD and Raman spectroscopy. The FT-IR results supported by Xray diffraction analysis confirmed the inclusion of oxygen moieties within the graphitic structure during the chemical oxidation step. Microscopic and spectroscopic analysis was used to confirm the stackings of graphene on the pencil electrode. The ERGO-PG-MFE, in combination with a complexing agents of [dimethylglyoxime (DMG) and Nioxime] and square-wave cathodic stripping voltammetry (SW-CSV), was evaluated towards the individual determination of Ni2+ and Co2+ respectively and simultaneous determination of both metals from the combination of DMG and Nioxime mixture. A single-step electrode pre-concentration approach was employed for the in-situ Hg-film electroplating, metal-chelate complex formation and its non-electrolytic adsorption at – 0.7 V for the individual analysis of Ni2+ and Co2+. The current response due to metal-ligand(s) complex reduction were studied as a function of experimental variables; deposition/accumulation potential, deposition/accumulation time, rotation speed, frequency and amplitude and carefully optimized for the individual determination of Ni2+and Co2+ and simultaneous determination of Ni2+ and Co2+ at low concentration levels (μg L-1) in 0.1 M NH3- NH4Cl buffer solution (pH 9.4) solution. The recorded limit of detection for the individual analysis of Ni2+and Co2+ was found to be 0.120 μg L-1 and 0.220 μg L-1 respectively, at an accumulation time of 120 s for both metals. The recorded limit of detection of the simultaneous analysis of Ni2+ and Co2+ was found to be 6.1 μg L-1 and 1.8 μg L-1 respectively. The ERGO-PG-MFE further demonstrated a highly selective stripping response toward all trace metal analysis. The testing of the applicability of graphene-based sensor and method in laboratory tap water samples was evaluated. This electrode was found to be sensitive enough to detect metal ions in the tap water samples at the 0.2 μg L-1 level for individual analysis and 0.001 μg L-1 for simultaneous, well below WHO standards.

Superconducting thin films are a possible alternative to bulk niobium for superconducting radio frequency cavity applications. Thin film cavities have produced larger Q0 than bulk niobium at low accelerating voltages [1], are less susceptible to external magnetic fields and therefore require less magnetic shielding than bulk niobium cavities [2] and can benefit from substrates which conduct heat more effectively than bulk niobium [3]. The major drawback for current thin film cavity technology is the large Q slope which is observed above accelerating gradients of 6 7 MV/m. The mechanism for the Q slope is not yet fully understood. Theories have been suggested but are not accepted by everyone within the scientific community [2, 4, 5, 6, 7]. It is assumed that a better understanding of the physical properties of superconducting films is required before the origins of the sharp Q slope can be elucidated. This study has been conducted to better understand the physical properties of superconducting thin films deposited by the magnetron sputtering process. In particular, superconducting niobium films have been deposited by high power impulse magnetron sputtering (HiPIMS) and tested by a wide range of analytical techniques as a function of the substrate temperature and applied bias during deposition. Analytical techniques which have been used include x-ray diffraction crystallography, Rutherford backscattering spectroscopy, scanning electron microscopy, residual resistance ratio, DC magnetometry and RF surface resistance measurements. Results showed that the application of an applied bias during deposition resulted in increased energy of bombarding ions and enhanced rates of surface diffusion and defect annihilation within the microstructure of a growing niobium film. However, large numbers of random complex defects formed once the energy of bombarding ions becomes too large. The systematic approach that was described to investigate the changing morphological and DC superconducting properties of deposited films, as a function of the applied bias, allowed the identification of which process conditions produce the fewest random complex defects. The same systematic investigations could be applied to any HiPIMS deposition facility to provide similar results. An important observation during the study is that the initial substrate conditions have a large influence on the properties of a deposited niobium film. Niobium films deposited onto polycrystalline copper substrate that was pre-annealed at 700 ˚C prior to deposition displayed more stable magnetic flux pinning, larger RRR and an enhanced resistance to the onset of flux penetration, than was observed for films deposited with a wide range of process conditions onto as received copper substrate. Superconductors other than niobium have been successfully deposited by HiPIMS and tested. Niobium titanium nitride thin films displayed a superconducting transition temperature up to 16.7 K, with a normal state resistivity as small as 45±7 μΩcm. The findings suggest that similar niobium titanium nitride thin films could produce smaller RF surface resistance than bulk niobium cavities at 4.2 K.

The rapid progress of n-type metal oxide thin film transistors (TFTs) has motivated research on p-type metal oxide TFTs in order to realise metal oxide-based CMOS circuits which enable low power consumption large-area electronics. Cuprous oxide (Cu2O) has previously been proposed as a suitable active layer for p-type metal oxide TFTs. The two most significant challenges for achieving good quality Cu2O TFTs are to overcome the low field-effect mobility and an unacceptably high off-state current that are a feature of devices that have been reported to date. This dissertation focuses on improving the carrier mobility, and identifying the main origins of the low field-effect mobility and high off-state current in Cu2O TFTs. This work has three major findings. The first major outcome is a demonstration that vacuum annealing can be used to improve the carrier mobility in Cu2O without phase conversion, such as oxidation (CuO) or oxide reduction (Cu). In order to allow an in-depth discussion on the main origins of the very low carrier mobility in as-deposited films and the mobility enhancement by annealing, a quantitative analysis of the relative dominance of the main conduction mechanisms (i.e. trap-limited and grain-boundary-limited conduction) is performed. This shows that the low carrier mobility of as-deposited Cu2O is due to significant grain-boundary-limited conduction. In contrast, after annealing, grain-boundary-limited conduction becomes insignificant due to a considerable reduction in the energy barrier height at grain boundaries, and therefore trap-limited conduction dominates. A further mobility improvement by an increase in annealing temperature is explained by a reduction in the effect of trap-limited conduction resulting from a decrease in tail state density. The second major outcome of this work is the observation that grain orientation ([111] or [100] direction) of sputter-deposited Cu2O can be varied by control of the incident ion-to-Cu flux ratio. Using this technique, a systematic investigation on the effect of grain orientation on carrier mobility in Cu2O thin films is presented, which shows that the [100] Cu2O grain orientation is more favourable for realising a high carrier mobility. In the third and final outcome of this thesis, the temperature dependence of the drain current as a function of gate voltage along with the C-V characteristics reveals that minority carriers (electrons) cause the high off-state current in Cu2O TFTs. In addition, it is observed that an abrupt lowering of the activation energy and pinning of the Fermi energy occur in the off-state, which is attributed to subgap states at 0.38 eV below the conduction band minimum. These findings provide readers with the understanding of the main origins of the low carrier mobility and high off-state current in Cu2O TFTs, and the future research direction for resolving these problems.

Zhao, Wei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Abstracts in English and Chinese. / Acknowledgements --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2. --- H-bonded Acenes- An Approach to Self- assembled Organic Semiconductors --- p.16 / Chapter 2.1 --- Introduction --- p.16 / Chapter 2.2 --- Result and discussion --- p.17 / Chapter 2.3 --- Experiment --- p.23 / Chapter Chapter 3. --- Transistors from a Conjugated Macrocycle Molecule: Field and Photo Effects --- p.30 / Chapter 3.1 --- Introduction --- p.30 / Chapter 3.2 --- Result and discussion --- p.31 / Chapter 3.3 --- Conclusion --- p.37 / Chapter 3.4 --- Experiment --- p.37 / Chapter Chapter 4 --- Synthesis of Soluble and liquid crystalline Conjugated Macrocylces --- p.48 / Chapter 4.1 --- Introduction --- p.48 / Chapter 4.2 --- Result and Discussion --- p.49 / Chapter 4.3 --- Conclusion --- p.54 / Chapter 4.4 --- Experiment --- p.55 / Appendix --- p.65

Lai, Kim Fung = 幼樑之振動與力學特性 / 黎劍鋒. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 99-102). / Abstracts in English and Chinese. / Lai, Kim Fung = You liang zhi zhen dong yu li xue te xing / Li, Jianfeng. / Chapter I --- Vibrations of Timoshenko Beams --- p.1 / Chapter 1 --- Introduction --- p.2 / Chapter 1.1 --- Overview --- p.2 / Chapter 1.2 --- Simple theory of static beam bending --- p.6 / Chapter 1.3 --- Foundation of problem --- p.7 / Chapter 1.4 --- Literature review --- p.12 / Chapter 1.4.1 --- Euler-Bernoulli Beam Theory (EBBT) --- p.12 / Chapter 1.4.2 --- Timoshenko Beam Theory (TBT) --- p.16 / Chapter 1.5 --- Preview of our results --- p.20 / Chapter 2 --- 3-D problem --- p.22 / Chapter 2.1 --- Elastic theory --- p.23 / Chapter 2.2 --- Boundary conditions --- p.24 / Chapter 2.3 --- Plane waves in uniform thin beams --- p.25 / Chapter 2.4 --- Solving order-by-order analytically --- p.26 / Chapter 2.5 --- Minimization approach --- p.36 / Chapter 3 --- 2-D problem --- p.50 / Chapter 3.1 --- Boundary conditions and effective moduli --- p.51 / Chapter 3.2 --- Expansion for thin beams --- p.54 / Chapter 3.3 --- Plane waves in uniform thin beam --- p.56 / Chapter 3.4 --- Boundary conditions --- p.57 / Chapter 3.5 --- Truncation --- p.58 / Chapter 3.6 --- Numerical solution --- p.58 / Chapter 3.7 --- Analytic results for soft mode --- p.60 / Chapter 3.8 --- EBBT and TBT for 2-D problem --- p.62 / Chapter 3.9 --- Analytic results for hard mode at q = 0 --- p.64 / Chapter 3.10 --- Higher-order corrections for hard mode --- p.66 / Chapter 4 --- Summary --- p.71 / Chapter II --- Vibrations of Single-Walled Carbon nanotubes --- p.73 / Chapter 5 --- Introduction --- p.74 / Chapter 5.1 --- General properties --- p.74 / Chapter 5.2 --- Graphene sheet --- p.76 / Chapter 5.3 --- Rolling up a graphene sheet --- p.78 / Chapter 5.4 --- Foundation of problem --- p.79 / Chapter 5.5 --- Literature review --- p.79 / Chapter 5.6 --- Preview of our results --- p.80 / Chapter 6 --- Structure and strain energy under zero stress --- p.81 / Chapter 6.1 --- Description of the structure --- p.81 / Chapter 6.2 --- Description of the strain energy --- p.83 / Chapter 6.3 --- Minimization of energy --- p.86 / Chapter 7 --- SWCNT under strain --- p.89 / Chapter 7.1 --- Subject to an axial strain --- p.89 / Chapter 7.2 --- Subject to a radial strain --- p.94 / Chapter 7.3 --- Subject to a torsional strain --- p.95 / Chapter 8 --- Summary --- p.98 / Bibliography --- p.99 / Chapter A --- "Expressing elastic moduli G, λ and M in terms of Y andv" --- p.103 / Chapter B --- Simplification of the functional E to a neat expression --- p.105 / Chapter C --- Expressing effective elastic moduli G' and M' in terms of Y' and v' --- p.106 / Chapter D --- Illustration of the lowest non-trivial truncation --- p.107 / Chapter E --- The proof of Self-adjointness of H(q) --- p.109 / Chapter F --- Proof of the identity KeVec= KeVel --- p.112

Wai, Kwai Fong = 錳氧化物 - 鈮摻雜之鈦酸鍶異構結的電流電壓關係測量 / 韋桂芳. / "Sept 2007." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / Wai, Kwai Fong = Meng yang hua wu - ni shan za zhi tai suan si yi gou jie de dian liu dian ya guan xi ce liang / Wei Guifang. / Acknowledgement / Abstract / 論文摘要 / Table of content / List of Figures / List of Tables / Appendix A / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Structure and properties of perovskite manganites / Chapter 1.2 --- Magnetoresistance (MR) / Chapter 1.3 --- Giant Magnetoresistance (GMR) / Chapter 1.4 --- Colossal Magnetoresistance (CMR) / Chapter 1.4.1 --- Exchange interaction and CMR / Chapter 1.5 --- p-n junction / Chapter 1.5.1 --- Fundamentals of a p-n homojunction / Chapter 1.5.2 --- Deviations from the Ideal Diode / Chapter 1.5.2.1 --- Zener breakdown / Chapter 1.5.2.2 --- Avalanche / Chapter 1.5.3 --- Heterojunction / Chapter 1.6 --- Research motivation / Chapter 1.7 --- Scope of the thesis / References / Chapter Chapter 2 --- Experimental details / Chapter 2.1 --- Thin film deposition / Chapter 2.1.1 --- Facing target sputtering / Chapter 2.1.2 --- Vacuum system / Chapter 2.1.3 --- Deposition procedure / Chapter 2.2 --- Oxygen annealing system / Chapter 2.3 --- Silver electrode coating apparatus / Chapter 2.4 --- Characterization / Chapter 2.4.1 --- Alpha-step profilometer / Chapter 2.4.2 --- X-ray diffractometer / Chapter 2.4.3 --- Electrical transport property measurement / Chapter 2.4.3.1 --- Measurement of resistance as a function of temperature (RT) / Chapter 2.4.3.2 --- Measurement of I-V characteristics of a junction / References / Chapter Chapter 3 --- Epitaxial LSMO/STON heterojunction / Chapter 3.1 --- Sample preparation / Chapter 3.2 --- Results and Analysis / Chapter 3.2.1 --- Structural analysis / Chapter 3.2.2 --- R-T measurement / Chapter 3.2.3 --- I-V measurement / Chapter 3.2.3.1 --- Analysis of diffusion voltage and breakdown voltage / Chapter 3.2.3.2 --- Construction of energy band diagram of LSMO/STON at room temperature / Chapter 3.2.3.3 --- Investigating how the energy band structure varies with the temperature / Chapter 3.2.3.4 --- Further development of the energy band analyzing method to wide-p/narrow-n heteroj unction / Chapter 3.2.3.5 --- Forward-biased deviations from ideal / Chapter 3.2.3.6 --- Discussion on the reasons for deviations from ideal / Chapter 3.2.4 --- MR determination / References / Chapter Chapter 4 --- Epitaxial [LSMO/PCMO] multilayers and p-n junction / Chapter 4.1 --- [LSMO/PCMO]/NGO multi-layered thin films / Chapter 4.1.1 --- Sample preparation / Chapter 4.1.2 --- Results and analysis / Chapter 4.1.2.1 --- Structural analysis / Chapter 4.1.2.2 --- R-T measurement / Chapter 4.2 --- [LSMO/PCMO]/STON multi-layered junction / Chapter 4.2.1 --- Sample preparation / Chapter 4.2.2 --- Results and analysis / Chapter 4.2.2.1 --- Structural analysis / Chapter 4.2.2.2 --- R-T measurement / Chapter 4.2.2.3 --- I-V measurement / Chapter 4.2.2.3.1 --- Analysis of diffusion voltage and breakdown voltage / Chapter 4.2.2.3.2 --- Investigating the energy band structure as a function of temperature / Chapter 4.2.2.3.3 --- Forward-biased deviations from an ideal junction diode / Chapter 4.2.2.3.4 --- Review on MR calculation / Chapter 4.2.2.3.5 --- Analysis of MR of [LSMO(8 A ) /PCMO(8 A)]/STON and LSMO/STON / References / Chapter Chapter 5 --- [La0 4Ca0.6MnO3/La0.8Ca0.2MnO3］p-n junction / Chapter 5.1 --- Sample preparation / Chapter 5.2 --- Result and analysis / Chapter 5.2.1 --- Structural analysis / Chapter 5.2.2 --- R-T measurement / Chapter 5.2.3 --- I-V measurement / Chapter 5.2.3.1 --- Analysis of diffusion voltage and breakdown voltage / Chapter 5.2.3.2 --- Investigating the energy band structure as a function of temperature / Chapter 5.2.3.3 --- Forward-biased deviations from ideal / Chapter 5.2.3.4 --- MR analysis / Chapter Chapter 6 --- Conclusion / Chapter 6.1 --- Conclusion / Chapter 6.2 --- Future outlook