Functional transport properties in complex transition metal oxides

Transition oxide materials have a long and high-flying history due to their attractive properties. They are well-known today for magnets, high temperature superconductors as well as promising electronic materials. For example, BaTiO3 and PbZrTiO3 are famous piezoelectric materials that are used in Micro-electric-mechanical system devices and VO2, a metal insulator transition material with a threshold temperature of 70 degrees is used to prevent over-heating of devices such as batteries. Herein, I address the newly investigated noble transport properties in (1) perovskite (La,Pr,Ca)MnO3 as a cryogenic non-volatile random access memory by using the phase change between charge-ordered insulating state and ferromagnetic metallic state, (2) ferroelectric BiFeO3: switchable photovoltaic effect by switching the poling direction of the sample. I also explored the newly investigated multiferroic property in transition metal compound Ca3Co2-xMnxO6 as well as the giant magnetic coercivity change induced by co-operative freezing in Ca3Co2O6.Ph.D.Includes bibliographical referencesIncludes vitaby Hee Taek Y