Positive temperature coefficient of resistivity effect in niobium-doped barium titanate ceramics obtained at low sintering temperature

A positive temperature coefficient of resistivity (PTCR) effect was observed for low temperature sintered Nb-doped BaTiO3 ceramics using YB6 as a sintering aid. A semiconducting BaTiO3 with good PTCR property was obtained at a low sintering temperature of 1150 °C because of the addition of YB6. Addition of 0.2 mol% Nb2O5 and 1 mol% of YB6 led to a low room-temperature resistivity and a resistivity jump of about 104. Room-temperature resistivity of the ceramics was controlled by the grain boundary resistivity which was related to the added amount of YB6 and the sintering temperature. YB6 only worked as a sintering aid to enhance the densification of semiconducting BaTiO3 ceramics at low sintering temperature.