Correlated Oxides: Material Physics and Devices

Abstract

In this work we study the metal-insulator transition in vanadium dioxide and samarium nickelate and the application of such transitions in electronic devices. Chapter 1 provides an introduction to the Mott metal-insulator transition mechanisms and an overview of the interplay between various degrees of freedom in correlated oxides. The phase transition in vanadium dioxide is presented as an example to emphasize the overarching electron-phonon and electron-electron interaction driven transition mechanisms. In Chapter 2, we describe the growth and structure-functionality relationship of thin film transition metal oxides. Chapter 3 goes on to examine the mechanism of voltage-triggered metal-insulator transition in vanadium dioxide two-terminal threshold switches through dynamic studies. Chapter 4 delves into the mechanism of conductance modulation in electrolyte-gated vanadium dioxide transistors, which reveals the importance of electrochemical effects versus electrostatic effects in these devices. Utilizing the idea of electrochemical doping, we designed and realized a strongly correlated insulating phase in samarium nickel oxide through electron doping with hydrogen and lithium interstitials in Chapter 5. Such techniques can be extended to other materials to achieve reversible and controllable carrier doping with high concentration to study the related physics.