Abstract

Thin films of vanadium dioxide exhibit a thermally induced semiconductor-to-metal phase transition near 67°C.^1,2,3 Below 67°C the material is a semiconductor with a monoclinic structure. Above 67°C it becomes metallic, transforming to a higher symmetry tetragonal structure. Conventionally deposited films display large changes in optical properties in the infrared spectral region; however, not much contrast is observed at visible wavelengths.⁴ They are bronze in transmission and do not change color appreciably when heated. The microstructure consists of tightly packed coherent grains ranging from 0.1 to 0.5 microns in diameter, depending on deposition conditions.

© 1988 Optical Society of America