Electrical behavior of ZnO-Bi{sub}(3/2)ZnSb{sub}(3/2)O{sub}(7-s) pyrochlore mixtures

摘要

ZnO-pyrochlore mixtures were prepared with different pyrochlore contents of 10, 1 5 and 25 mass %. Mixtures sintered between 1050 and 1200℃ contained mainly ZnO and pyrochlore but traces of Bi2O3 and spinel were also observed. The microstructure of the mixtures consisted mainly of ZnO with intergranular spinel and pyrochlore phases. Electrical measurements revealed that pyrochlore containing mixtures show varistor behaviour. The nonlinearity constant was < 10 for all the mixtures and did not show a consistent increase or decrease with changes of either sintering temperature or amount of pyrochlore. The mixtures gave breakdown and barrier voltages of between 65...230 V and 2...3,7 V respectively.