Structure and property of Y and YF3 doped barium titanate

Positive Temperature Coefficient of Resistivity (PTCR) materials based on Yttrium and Yttrium Fluoride (YF3) doped Barium titanate (BaTiO3) ceramics were prepared in different sintering atmospheres, respectively. The effects of sintering atmospheres on the microstructure, property and mechanism of substitution of doped BaTiO3 ceramics were investigated by the means of XRD, SEM, XRF and R-T measuring instrument. Sintering in a low oxygen partial atmosphere can increase the densities of Y and YF3 doped BaTiO3 and make grain particle grow. Both Y and YF3 doped BaTiO3 ceramics are n-type semiconductor in which Y substitutes A-site and F substitutes O-site. Sintered in a argon atmosphere, Y doped BaTiO3 exhibited little PTCR effect, however, an anomalous PTCR effect was observed when 0.3mol% YF3 doped BaTiO3 ceramics was fired in Argon atmosphere. This phenomenon may be explained by a new O site substitution mechanism.