Транспортные свойства керамики AgNbO3

Abstract

Monoclinic and cubic perovskite phases of AgNbO3 have been demonstrated to co-exist in air and oxygen atmospheres at 300-1100 K, whereas reducing oxygen partial pressure results in a transition of the monoclinic phase into the cubic one and in metallic silver formation. Electrical conductivity of the silver niobate is predominantly electronic. No oxygen anionic or silver cationic component of the conductivity has been found by the e.m.f. and Tubandt's methods. Thermal expansion coefficient of AgNbO3 ceramics has been calculated from the dilatometric data in the temperature range 300 to 1100 K to be (11,1 ± 0,2) x 10-6 K-1.