BaTiO3 and SrBiO2.5 two phase system NTC thermistors

BaTiO₃-based materials doped with SrBiO_2.5 only show negative temperature coefficient effect over a wide temperature range. X-ray diffraction analysis displays that major phases present in the sintered bodies were the Ba_0.5Sr_0.5TiO₃ compounds with a cubic structure and the BaBiO₃ compounds with a monoclinic structure. The mean grain size of samples remains unchanged with an increase from 20 to 50 in SrBiO_2.5 content. The values of ρ ₂₅ and B _25/125 constants of thermistors decreased with an increase in SrBiO_2.5 content. The resistivity measured at other temperatures showed basically the same behavior as that at room temperature, irrespective of the measuring temperature.