New negative temperature coefficient thermistor ceramics in Mn-doped CaCu3−xMnxTi4O12 (0≤x≤1) system

New negative temperature coefficient (NTC) ceramics based on CaCu3−xMnxTi4O12 (0≤x≤1) compositions have been investigated. The grain size of the CaCu3−xMnxTi4O12 samples decreases at first and then increases with increasing Mn content. The X-ray photoelectron spectroscopy analysis corroborates the presence of Mn3+ and Mn4+ in Mn-doped samples, which results in a decrease in the activation energy. All the NTC thermistors prepared show a linear relationship between the natural logarithm of the resistivity and the reciprocal temperature, indicative of NTC characteristics. The Mn-doped CaCu3−xMnxTi4O12 NTC thermistors provide various electrical properties, depending on Mn content. The values of ρ25, B constant and activation energy of the NTC thermistors are in the range of 2.22×106–3.22×108 Ω cm, 5488–8031 K, and 0.473–0.692 eV, respectively.