Newnegativetemperaturecoefficient (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+ inMn-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-dopedCaCu3-xMnxTi4O12 NTC thermistors provide various electrical properties, depending on Mn content. The values of p25, B constant and activation energy of the NTC thermistors are in the range of 2.22 x 10(6)-3.22 x 10(-8) Omega cm, 5488-8031 K, and 0.473-0.692 eV, respectively.
Xinjiang Tech Inst Phys & Chem CAS, Xinjiang Key Lab Elect Informat Mat & Devices, Key Lab Funct Mat & Devices Special Environm CAS, Urumqi 830011, Peoples R China;Univ Chinese Acad Sci, Beijing 100049, Peoples R China;Alfred Univ, New York State Coll Ceram, Kazuo Inamori Sch Engn, Alfred, NY 14802 USA;Aston Univ, Sch Engn & Appl Sci, Birmingham B4 7ET, W Midlands, England
Zhang, Bo,Zhao, Qing,Chang, Aimin,et al. New negative temperature coefficient thermistor ceramics in Mn-doped CaCu3-xMnxTi4O12 (0 <= x <= 1) system[J]. Ceramics International,2014,40(7 PART B):11221-11227.