Optical and electrical properties of rare earth and transition metal oxide thin films and crystals

The author reports the first explanation of the novel switching mechanism in two terminal devices based on the layered material V2O5 · 1.6H2O. The switching is shown to be associated with the existence of a current-induced channel between the contacts. Resistivity data on the channel exhibit a sharp transition at T = 334 K, which is also the average sample temperature above which the device was observed to stop switching. A novel single-target planar magnetron sputtering system was developed to sputter various high-Tc superconducting thin films. Superconducting transition temperature of the films prepared in this system are 80 K and 81 K for YBa2Cu3O7-δ and HoBa2Cu3O7-δ films, respectively. The first optical studies on single crystal samples of Nd2-XCeXCuO4-δ (X = 0, 0.2) over a wide energy range (0.005 to 6 eV) is presented. An unusually broad and strong mid-infrared (IR) absorption band was observed