Chemistry Letters, Vol.31, No.3, 412-413, 2002
High temperature PTC thermistor using Ba cobaltite
It was found that partially Fe-substituted Ba cobaltite, BaCo0.7Fe0.3O3-delta shows sharp PTC behavior at temperature above 850 degreesC. As revealed by XRD measurements, the PTC behavior is accompanied by phase transformation between hexagonal perovskite structure (low temperature) and cubic one (high temperature).