Electrical and Optical Properties of High Quality Crystalline V2O4 near the Semiconductor-Metal Transition Temperature

The object of this research is to contribute to our knowledge and understanding of the electrical and optical properties of high quality crystalline V2O4. This material exhibits a phase change at 65 degrees C which is accompanied by a change in electrical resistivity of five orders of magnitude which is often referred to as a semiconductor-metal transition. Several theories had been suggested to explain the nature of this transition, but sufficient experimental evidence to determine which, if any, of these theories applied to V2O4 was not available at the time this research began. In particular, it was not known whether or not V2O4 was a Mott insulator below the transition temperature, or whether a band theory approach such as the Adler-Brooks theory might describe the transition. This research has resulted in experimental measurements and theoretical analysis which permit a tentative explanation of the transition mechanism to be made.