Investigation Of Electronic Structure Of Transition Metal Oxides Exhibiting Metal-insulator Transitions And Related Phenomena

Download or read book Investigation Of Electronic Structure Of Transition Metal Oxides Exhibiting Metal-insulator Transitions And Related Phenomena written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal oxides have proven to be a fertile research area for condensed matter physicists due to the fascinating array of superconducting, magnetic and electronic properties they exhibit. A particular resurgence of intense activity in investigating the properties of these systems followed the discovery of high temperature superconductivity in the cuprates, colossal magnetoresistance in the manganites, ferroelectricity in the cobaltites and simultaneous ferroelectric and ferromagnetic ordering in the manganites. These diverse properties of transition metal compounds arise due to the presence of strong electron-electron interactions within the transition element 3d states. Indeed, it is the competition between the localizing effects of such interactions and the comparable hopping strengths driving the system towards delocalization, that is responsible for these wide spectrum of interesting properties. In terms of theoretical and fundamental issues, electronic structure of transition metal oxides play a most important role, providing a testing ground for new many-body theoretical approaches treating the correlation problem at various levels of approximations. In addition to this rich spectrum of properties, metal-insulator transitions often occur and can even be coincident with structural or magnetic changes due to the strong coupling between charge, magnetic and lattice degrees of freedom. However, in spite of the immense activities in this area, the underlying phenomena is not yet completely understood. A careful investigation of the electronic structure of these systems will help in the microscopic understanding of these and photoelectron spectroscopy has been established as the most powerful tool for investigating the electronic structures of these systems. In this thesis we investigate the electronic structures of some of these transition metal oxides and the metal-insulator transition as a function of electron correlation strength and doping of charge car.