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

Abstract

The perovskite CaMnxZr(1-x)O3 (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, CaMnO3, 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, Ea, 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/R0) was found to be lower than 4.3%, which is an indication of an excellent high temperature stability of the CMZO ceramic material.