Pre-exponential factor in ð‘�?-Se75In25â€�?�ð�?�¥Pbð‘�? thin films

[摘要] Temperature dependence of d.c. conductivity is studied in ð‘�?-Se⁷⁵In_{25â€�?�ð�?��?}Pb_ð‘�? thin films where ð‘�? is varied from 0â€�??10. From these measurements, the values of the pre-exponential factor (𝜎₀) and activation energy (𝛥ð�?) are calculated for each glassy alloy. An approximate linear dependence of ln 𝜎₀ on 𝛥ð�? is observed in this glassy system with good agreement between the expected and calculated 𝜎₀ values using Meyerâ€�?�Neldel rule. Linear dependence of ln𝜎₀ on 𝛥ð�? in case of amorphous materials indicates that the conduction band tails a finite energy distance towards the valence band and Fermi level is controlled by fixed dominant hole levels deeper in the gap.

[学科分类] 材料工程

[关键词] Chalcogenide glasses;Meyerâ€�?�Neldel rule;conductivity pre-exponential factor.