PTCR behaviour of Ba2LaBiO6-doped BaTiO3 ceramics

The influences of Ba2LaBiO6 content on the electrical property and the microstructure of BaTiO3-based materials have been studied. At a low dopant concentration the grain size is influenced significantly by the donor concentration. With an increase in Ba2LaBiO6 content the grain size decreases rapidly. All the prepared Ba2LaBiO6 doping BaTiO3-based thermistors show typical PTC effect. As the amount of Ba2LaBiO6 added in BaTiO3-based ceramics increases, the room temperature resistivity appears to exhibit a minimum value. At high Ba2LaBiO6 content (≥0.15), the room temperature resistivity increased again with increasing Ba2LaBiO6 content. At a given content of Ba2LaBiO6, the influence of sintering temperature on the electrical properties of samples has been investigated. A maximum of ρmax/ρmin ratio was obtained at the sintering temperature equal to 1270 °C at a given content of Ba2LaBiO6.