Complex oxide materials, especially the ABO3-type perovskite materials, have been attracting growing scientific interest due to their unique electro-optical properties, leading to photorefractive effects that form the basis for such devices as holographic storage, optical data processing and phase conjugation. The optical and mechanical properties of non-metals are strongly affected by the defects and impurities that are unavoidable in any real material. Nanoscopically sized surface effects play an important role, especially in multi-layered ABO3 structures, which are good candidates for high capacity memory cells.
The 51 papers presented here report the latest developments and new results and will greatly stimulate progress in high-tech technologies using perovskite materials.

Zusammenfassung
Proceedings of the NATO Advanced Research Workshop, Jurmala, Latvia, 23-25 August, 1999

Inhalt
I Modelling of Defects and Surfaces.- Quantum Mechanical Modelling of Pure and Defective KNbO3Perovskites.- First-Principles Simulation of Substitutional Defects in Perovskites.- Point Defects, Dielectric Relaxation and Conductivity in Ferroelectric Perovskites.- Use and Limitations of the Shell Model in Calculations on Perovskites.- What can We Learn about Perfect and Defective MgO(001) Surface Using Density Functional Theory?.- Defect Calculations for Yttrium Aluminum Perovskite and Garnet Crystals.- Theoretical Studies of Impurity Doped and Undoped BaTiO3and SrTiO3Crystals.- II Experimental Study of Structure and Basic Properties; HTSC.- EPR Investigations of Small Electron and Hole Polarons in Oxide Perovskites.- Nb4+Polaron and Ti3+Shallow Donor Jahn-Teller Centers in LiNbO3Systems.- Polarons and Bipolarons in Oxides.- Structural Distortions and Oxygen Local Dynamic Instabilities in Superconducting Perovskites.- Subpicosecond Laser Spectroscopy of Blue-Light-Induced Absorbtion in KNbO3and LiNbO3.- Extended X-Ray Absorption Fine Structure Spectroscopy of Perovskite-Type Compounds.- X-Ray Absorption Spectroscopy of (Pb1-xLax)(Zr0.65Ti0.35)O3at the ZrKand PbL3Edges.- IR Spectroscopy of Monoclinic Tungsten Oxide.- Low Temperature Optical Absorption by Magnons in KNiF3and NiO Single-Crystals.- The Metastable Superior Phases in Bi-2212 Perovskite-Like High-Temperature Superconductor.- Surface-Induced Drift and Selforganization Features of Microwave Losses in High-T. Superconductor Perovskites.- III Effects on Surfaces, Interfaces and Thin Films.- QM Study on Transition Metal Perovskites.- Chemisorption by Simple Oxide Surfaces.- Theoretical Simulations of Surface Relaxation for Perovskite Titanates.- Wetting of Domain Walls in Perovskites.- Ferroelectric Soft-Mode Spectrocopy in Disordered Bulk and Thin-Film Perovskites.- Metals on Metal Oxides: Study of Adsorption Mechanisms with the Metastable Impact Electron Spectroscopy (MIES).- Properties of Multiphase Interfaces on the Tungsten Trioxide Particles in the Thin Films.- The Joining of LiNbO3Quartz, TIBr-TII and Other Optical Materials by the Use of Thin Metal Films as Bonding Agents.- Experimental Study of Texture and Self-Polarization of Sol-Gel Derived PZT Thin Films.- Experimental Study of Heat Properties of Ba1-xSrxTiO3Thin Films on a Substrate.- Synthesis of Lead Zirconate Antiferroelectric Thin Films by Sol-Gel Processing.- IV Defects and Phase Transitions.- Infrared Spectroscopy of OH-induced Defects in Fluoroperovskites.- Hydrogen-Related Effects in Oxides.- Ion-Beam-Induced Defects and Defects Interactions in Perovskite-Structure Titanates.- Phase Transitions in Incipient Ferroelectrics of Perovskite Structure with Impurities.- Influence of Structure Ordering, Defects and External Conditions on Properties of Ferroelectric Perovskites.- Phase Transition Anomalies in Crystals with Defects.- Defects in Perovskites Induced by Illumination.- Defect Luminescence Study in Tetragonal GeO2Crystals.- Thermally Stimulated Ionic and Electronic Processes and Radiation-Induced Defect Annealing in LiBaF3Crystals.- Radiation Defects in LiBaF3Perovskites.- Radiation Induced Defects in Yttrium Aluminium Perovskite.- Laser-Calorimetric Study of Fundamental Absorption Edge in Pb,La(ZrTi)O3(PLZT) Perovskite Ceramics.- Mesoscopic Scale Polarization Inhomogeneities in Electrooptic Ceramics: the Chaotic Phase Screen Model.- New Ideas in Relaxor Theory.- V Advanced Technologies, New Perovskite Materials and Applications.- Nature of the Defects Induced by Photoinjection of Hydrogen in Transition in Metal Oxides.- Assessment of Surface Quality by SHG in Oxide Crystals.- Perovskite Materials for Optical Filtering and the Generation of Coherent Radiation.- Preparation and Properties of La1-xAxMnO3(A = Ca,Sr) Single Crystals.- Oxygen Diffusion in Donor Doped SrTiO3: Influence of Thermal Pretreatment.- Effect of Reducing and Oxidizing Atmospheres on the PTCR Properties of BaTiO3.- New Approach for Boundary Conditions: Space Charge Controlled Concentrations of Cation Vacancies in Donor Doped SiTiO3for Short Diffusion Length.- Defect Luminescence of LiBaF3Perovskites.- Author Index.