Polaronic transport in antimony-vanadium tellurate glasses at high temperatures

The ternary bulk glasses of the form (60-x)V2O5-40TeO(2)-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 4.80x10(-6) -1.08x10(-4) S cm(-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 alpha) was found to be 2.26x10(8) cm(-1) for samples with x >= 8 mol%.