Electrical conductivity of Cu-x(As0.4Se0.3Te0.3)(100-x) glasses

Results of the de electrical conductivity (sigma) measurements (from 90 to 420 Kj on 15 com positions of the Cu-x(As(0.4)Se(0.3)Teo(0.3))(100-x) glass es (x from 0 to 30) are presented. Similar to that observed [1] in the comp osition dependencies of the mean atomic volume (V) and the glass transition temperature (T-g) of these glasses, it is possible to delineate three regi ons in the composition dependence of the sigma of these glasses. (i) For ad dition of Cu up to 1 at %, the sigma register a decrease compared to that o f the parent Aso(0.4)Seo(0.3)Teo(0.3) glass. (ii) For Cu > 1 at %, the cond uction activation energy (Delta E) and the pre-exponential factor (C) decre ase, with a concomitant increase in a (at 250 K) by about six orders of mag nitude. (iii) Both Delta E and C show saturation for Cu > 23 at %. The a-co mposition data are examined using the model developed earlier [1] to unders tand, the V land T-g)-composition dependencies of these glasses. (C) 1999 K luwer Academic Publishers.