Effects of Manganese on Highly Donor-Doped Barium Titanate Ceramics with Resistivity of Positive Temperature Coefficient

Highly donor-doped ceramics with composition of Ba0.984Y0.016TiO3 were prepared for thermistors with positive temperature coefficient of resistivity (PTCR) via a route of solid reaction, reducing sintering and aerial oxidation. The effects of Mn additive were investigated on the ceramic characteristics of composition, morphology and electrical properties. The Mn incorporation affected little on ceramic composition but resulted in an obvious change in ceramic morphology, which illustrated the average grain size of 1.16, 1.65 and 1.01 μm for Mn addition amount of 0, 0.0005 and 0.0010, respectively. The grain growth, together with the Mn additive, influenced the electrical properties of room temperature resistivity, PTCR jump, donor and acceptor densities as well as the depletion layer width.