CONDUCTIVITY OF SELENIUM IN SEMICONDUCTOR-METAL TRANSITION REGION AT HIGH TEMPERATURES AND PRESSURES

Abstract
Electrical conductivity of Selenum has been measured in semiconductor metal transition region at pressures up to 0.4 GPa and temperatures up to 2100 K. It was observed that the origin of semiconductor-metal transition shifted to lower temperatures and metallic conductivity region was expanded. With pressure increasing the metallic conductivity level gradually increases from 10² Ω^-1 cm^-1 at 0.1 GPa to 10³ Ω^-lcm^-1 at 0.4 GPa. On the other hand the metal-isolator transition shifts apparently to higher temperatures with pressure increasing. These data are compared with results on metal-nonmetal transition in arsenic and mercury. The character of semiconductor-metal and metal-isolator transitions is discussed.