engleski

High Electronically Conductive Tungsten Phosphate Glass-Ceramics

High electronically conductive tungsten phosphate glass-ceramics have been prepared by the controlled crystallization of binary 60WO3– 40P2O5 glass in the temperature range from 700 to 935 ◦C and for 1 to 24 h. The substantial increase in the conductivity for four orders of magnitude is a result of the formation of electronically conductive W2O3(PO4)2 and WO3 phases. At low crystallization temperature the dominant W2O3(PO4)2 phase is created, whereas at 935 ◦C for 24 h the formation of semiconducting WO3 crystallites of an average size of 80 nm enhances the conductivity to the highest value of 1.64 × 10−4 (W cm)–1 at 30 ◦C. The course of the crystallization and its impact on this exceptionally high electronic transport of binary tungsten phosphate glass- ceramics has been discussed in detail. Since such highly electronically conductive WO3-based glass-ceramics have a great potential as cathode/anode materials in solid state batteries and as electrocatalysts in fuel cells, it is of interest to provide a novel insight into the improvement of their electrical properties.

binary tungsten phosphate glass-ceramics ; crystallization ; electronic transport ; W2O3(PO4)2 phase ; semiconducting WO3 phase

This article belongs to the Special Issue Preparation and Application of Nanostructured Glass–Ceramics and Nanocomposites.