Dielectric and ferroelectric properties of Ba 0.8Sr 0.2Ti 1−5 x/4 Nb xO 3 ceramics

Abstract

Ba 0.8Sr 0.2Ti 1−5 x/4 Nb x O 3 ceramics, x = 0, 0.01, 0.05, 0.10, were fabricated by conventional solid-state reaction. With increasing niobium content the ferroelectric phase transition temperature decreases linearly, and the dispersivity of the transition increases. Niobium B-site decreases transition temperature more pronounced than Sr 2+ at A-site. The heterovalent substitution of Nb 5+ in low content causes local defect dipole, while more substitutions introduce disorder to disturb the long-range dipole correlation. Ba 0.8Sr 0.2Ti 1−0.5/4Nb 0.1O 3 ceramic shows weak ferroelectric loop at room temperature far from its transition temperature, 153 K.