Oxides form a broad subject area of research and technology development which encompasses different disciplines such as materials science, solid state chemistry, physics etc. The aim of this book is to demonstrate the interplay of these fields and to provide an introduction to the techniques and methodologies involving film growth, characterization and device processing. The literature in this field is thus fairly scattered in different research journals covering one or the other aspect of the specific activity. This situation calls for a book that will consolidate this information and thus enable a beginner as well as an expert to get an overall perspective of the field, its foundations, and its projected progress.

Our understanding and control of epitaxial oxide heterostructures has progressed along multiple frontiers including magnetic, dielectric, ferroelectric, and superconducting oxide materials. This has resulted in both independent rediscovery and the successful borrowing of ideas from ceramic science, solid-state physics, and semiconductor epitaxy. A new field of materials science has emerged which aims at the use of the intrinsic properties of various oxide materials in single-crystal thin-film form. Exploiting the potential of these materials, however, will only be possible if many fundamental and engineering questions can be answered. This book represents continued progress toward fulfilling that promise. Technical information on epitaxial oxide thin films from industry, academia and government laboratories is presented. Topics include: dielectrics; ferroelectrics; optics; superconductors; magnetics; magnetoresistance.

Integration of multi-functional oxide thin films with semiconductors has attracted considerable attention in recent years due to their potential applications in sensing and logic functionalities that can be incorporated in future system-on-a-chip devices. III-V semiconductor, for example, GaAs, have higher saturated electron velocity and mobility allowing transistors based on GaAs to operate at a much higher frequency with less noise compared to Si. In addition, because of its direct bandgap a number of efficient optical devices are possible and by oxide integrating with other III-V semiconductors the wavelengths can be made tunable through hetero-engineering of the bandgap. This study, based on the use of SrTiO3 (STO) films grown on GaAs (001) substrates by molecular beam epitaxy (MBE) as an intermediate buffer layer for the hetero-epitaxial growth of ferromagnetic La0.7Sr0.3MnO3 (LSMO) and room temperature multiferroic BiFeO3 (BFO) thin films and superlattice structures using pulsed laser deposition (PLD). The properties of the multilayer thin films in terms of growth modes, lattice spacing/strain, interface structures and texture were characterized by the in-situ reflection high energy electron diffraction (RHEED). The crystalline quality and chemical composition of the complex oxide heterostructures were investigated by a combination of X-ray diffraction (XRD) and X-ray photoelectron absorption spectroscopy (XPS). Surface morphology, piezo-response with domain structure, and ferroelectric switching observations were carried out on the thin film samples using a scanning probe microscope operated as a piezoresponse force microscopy (PFM) in the contact mode. The magnetization measurements with field cooling exhibit a surprising increment in magnetic moment with enhanced magnetic hysteresis squareness. This is the effect of exchange interaction between the antiferromagnetic BFO and the ferromagnetic LSMO at the interface. The integration of BFO materials with LSMO on GaAs substrate also facilitated the demonstration of resistive random access memory (ReRAM) devices which can be faster with lower energy consumption compared to present commercial technologies. Ferroelectric switching observations using piezoresponse force microscopy show polarization switching demonstrating its potential for read-write operation in NVM devices. The ferroelectric and electrical characterization exhibit strong resistive switching with low SET/RESET voltages. Furthermore, a prototypical epitaxial field effect transistor based on multiferroic BFO as the gate dielectric and ferromagnetic LSMO as the conducting channel was also demonstrated. The device exhibits a modulation in channel conductance with high ON/OFF ratio. The measured nanostructure and physical-compositional results from the multilayer are correlated with their corresponding dielectric, piezoelectric, and ferroelectric properties. These results provide an understanding of the heteroepitaxial growth of ferroelectric (FE)-antiferromagnetic (AFM) BFO on ferromagnetic LSMO as a simple thin film or superlattice structure, integrated on STO buffered GaAs (001) with full control over the interface structure at the atomic-scale. This work also represents the first step toward the realization of magnetoelectronic devices integrated with GaAs (001).

With an in-depth exploration of the following topics, this book covers the broad uses of zinc oxide within the fields of materials science and engineering:- Recent advances in bulk , thin film and nanowire growth of ZnO (including MBE, MOCVD and PLD), - The characterization of the resulting material (including the related ternary systems ZgMgO and ZnCdO), - Improvements in device processing modules (including ion implantation for doping and isolation ,Ohmic and Schottky contacts , wet and dry etching), - The role of impurities and defects on materials properties - Applications of ZnO in UV light emitters/detectors, gas, biological and chemical-sensing, transparent electronics, spintronics and thin film