Effect of annealing on d.c. conductivity of V2O5-SnO-TeO2glasses

✍ Scribed by Hidetsugu Mori; Hironobu Sakata

• Publisher: Springer
• Year: 1995
• Tongue: English
• Weight: 485 KB
• Volume: 30
• Category: Article
• ISSN: 0022-2461
• DOI: 10.1007/bf00361522

✦ Synopsis

The d.c. conductivity (c~) of V2Os-SnO-TeO2 glasses prepared by the press-quenching method was studied at temperatures from room temperature (RT) to 473 K, and the effect of annealing on cy was investigated. The conductivity of 50V20~. 20SnO. 30TeO2 glass was determined to be 3.98x 10 -4 Scm -1 at 473 K and was unchanged for annealing (6-48 h) at 493 K, lower than Tg=501 K, while its density increased with annealing time. These glasses were found to be n-type semiconductors, and the conduction was confirmed to be due to adiabatic small polaron hopping for VzO5 > 50 mol%, and non-adiabatic for V205 < 50 mol %. The activation energy for conduction, W, decreased with annealing time. Variations in oxygen molar volume of the glasses with annealing time inferred a change in glass structure, from loosely to closely packed, resulting in a decrease in vanadium ion spacing with annealing. This caused an increase in the polaron band width, producing a decrease in polaron hopping energy and VIA. The effect of annealing time on the density of 50V2Os. 20SnO-30TeO2 glass was explained adequately by Winter's formula.