COMPOSITIONAL DEPENDENCE OF HIGH-PRESSURE RESISTIVITY BEHAVIOR OF CU-GE-TE GLASSES

Electrical resistivity measurements tinder pressures at ambient and lo w temperatures have been carried out on bulk, melt quenched CuxGe15Te8 5-x glasses (2<x<10) in an opposed anvil set up. The resistivities of these samples are found to decrease continuously with pressure, changi ng by about six orders of magnitude around 4 GPa pressure. The variati on of conductivity activation energy with pressure also confirms the c ontinuous metallisation of Cu-Ge-Te samples. The composition dependenc e of properties such as resistivity at ambient conditions, the pressur e derivative of resistance (d rho/dp), activation energy for electrica l conduction at different pressures etc, is found to exhibit anomalies at the composition 5 at% Cu. These results are explained on the basis of the rigidity percolation in chalcogenide network glasses.