High pressure studies on the electrical resistivity of As–Te–bond Si glasses and the effect of network topological thresholds

Abstract

The variation of resistivity in an amorphous As₃₀Te_70−x Si _x system of glasses with high pressure has been studied for pressures up to 8 GPa. It is found that the electrical resistivity and the conduction activation energy decrease continuously with increase in pressure, and samples become metallic in the pressure range 1.0–2.0 GPa. Temperature variation studies carried out at a pressure of 0.92 GPa show that the activation energies lie in the range 0.16–0.18 eV. Studies on the composition/average co-ordination number ⟨ r⟩ dependence of normalized electrical resistivity at different pressures indicate that rigidity percolation is extended, the onset of the intermediate phase is around ⟨ r⟩=2.44, and completion at ⟨ r⟩=2.56, respectively, while the chemical threshold is at ⟨ r⟩=2.67. These results compare favorably with those obtained from electrical switching and differential scanning calorimetric studies.

Keywords:

• chalcogenides
• high pressure
• electrical resistivity
• topological thresholds

Acknowledgements

Deepti Verma is grateful to M. Anbarasu for valuable help and management of M.S. Ramaiah College for their support and encouragement.