Nature of an intergranular thin−film phase in a highly non−Ohmic metal oxide varistor

Abstract
A detailed examination by transmission electron microscopy and selected−area diffraction revealed that the thin−film intergranular phase in a highly non−Ohmic multicomponent metal oxide varistor system based on ZnO with small additions of antimony, bismuth, cobalt, manganese, and tin oxides is amorphous and is chemically related to a Bi2O3−rich pyrochlore coexisting in the ceramic.