Growth structural optical and mechanical properties of certain rare earth perovskites and pyrochlore titanates single crystals

Abstract

Crystals have captivated mankind for thousands of years in the newlineforms of snowflakes, minerals or jewels. During the last five decades, newlinecrystals have fascinated research in applications as materials for newlineelectronics, optoelectronics and synthetic gemstones. Hence, single newlinecrystal growth has become scientifically and technologically important. newlineSingle crystals possess a repetitive structure and are defined by longrange atomic order. Due to this, single crystals have rigidity, shape, and newlinemechanical strength. It is a great challenge to grow crack free highquality single crystals and the extra effort in growing defect-free crystals newlineis justified due to its outstanding applications. The growth of nearly newlinedefect-free crystals is essential for studying the crystal structure, newlinephysical properties leading to high-performance device applications. A newlinecombination of science, technology and art is required to achieve good newlinequality single crystals. This is due to the complexity of the process, newlinewhere typically ten or more growth parameters have to be optimized and newlinethe complete understanding of the process is a major task owing to its newlinemultidisciplinary nature. The thesis deals with the synthesis, growth and newlineinvestigation of certain rare earth perovskites such as YAlO3 and Cu: newlineYAlO3, pyrochlore titanates Gd2Ti2O7 and Y2Ti2O7 and layered newlineperovskite structure Sr2Nb2O7. newline The thesis consists of seven chapters. Chapter 1 gives a brief newlineintroduction of the crystals and their defects. It also includes the newlinestructural arrangements in ternary oxide materials specifically newlineperovskites (YAlO3 and Cu: YAlO3), pyrochlores (Y2Ti2O7 and newlineGd2Ti2O7) and layered perovskite structure (Sr2Nb2O7) a newline