CaMnxZr(1-x)O3: A novel NTC thermo-sensitive ceramic for applications in a wide temperature range

The perovskite CaMn x Zr (1- x ) O 3 ( x  = 0, 0.05, 0.10, 0.15) (CMZO) NTC (Negative Thermal Coefficient) thermo-sensitive ceramic were prepared by the solid phase method that can be used as high temperature thermistor materials in the range of 200–1200 °C.The XRD pattern showed that CMZO is a finite solid solution and that a second phase, CaMnO 3 , will be formed after exceeding the solid solution limit (i.e., at x  = 0.1). The thermal constant B value was found to decrease from 19521 K to 9217–9535 K, with a corresponding decrease in activation energy , E a , from 1.69 eV to 0.82 eV. The Nyquist plot indicates that the grain boundary resistance determines the overall complex impedance. Moreover, the aging drift rate (ΔR/R 0 ) was found to be lower than 4.3%, which is an indication of an excellent high temperature stability of the CMZO ceramic material.