Abstract
Ceramic di-zinc stannate, Zn2SnO4, as-sintered, is an insulating material having electrical conductivity of the order of 10exp(-9) /ohm.cm. After suitable heat-treatment in a reducing atmosphere, its conductivity increases dramatically towards 100/ohm.cm and it changes colour from white to dark grey. The conducting material has been assessed as a possible replacement for cadmium oxide and tin oxide in conventional composite contacts, being superior in stability and conductivity. Samples of sintered and reduced Zn2SnO4 were prepared and then mixed with metallic silver for comparison with Ag/CdO and Ag/SnO2 composites. The suitability of Ag/Zn2SnO4 composites for application in this way was assessed with a simple contact arrangement and subjected to a typical life test. 7 refs.