HIGH-PRESSURE ELECTRICAL MEASUREMENTS ON GE-TE-SE GLASSES

Electrical resistivity measurements have been carried out on bulk Ge-T e-Se glasses in a Bridgman anvil System. The resistivity of the Ge-Te- Se samples is found to decrease continuously with increasing pressure, with the metallization occurring around 8 GPa. Ge20TexSe80-x glasses (10 less than or equal to x less than or equal to 50) with the mean co -ordination number Z(av) = 2.4 exhibit a plateau in resistivity up to about 4 GPa pressure, followed by a continuous decrease to metallic va lues. On the other hand, Ge10TexSe90-x glasses (10 less than or equal to x less than or equal to 40) having Z(av) = 2.2, exhibit a smaller p lateau (only up to 1 GPa), followed by a decrease in resistivity with pressure. This subtle difference in the high pressure resistivity of G e-Te-Se glasses with Z(av) < 2.4 and Z(av) greater than or equal to 2. 4 can be associated with the changes in the local structure of the cha lcogenide glasses with composition.