داریوش سوری

The ternary bulk glasses of the form (60-x)V2O5- 40TeO2-xSb with 0≤x≤15 (in mol%) were prepared by using the standard melt quenching technique. The dc electrical conductivity of the mentioned samples was investigated within the temperature range of 296 - 408 K. The dc conductivities at 370 K, with values in the range of 4.80×10 -6- 1.08×10 -4 Scm -1, were found to decrease with increase of Sb content. The experimental temperature- dependency of conductivity and the variation of the pre-exponential factor were interpreted in terms of polaron hopping theory. It founds that within the studied temperature range, the non-adiabatic small polaron hopping (NASPH) mechanism for electrons between different valent states of vanadium ions is applicable. The ratio of wave function decay (tunneling factor α ) was found to be 2.26× 10 8 cm-1 for samples with x≥8 mol%.