Resistance-temperature characteristics of a new high-temperature thermistor ceramics of Mn-doping Ba–Ca–Zr–Ti–O system

The Mn-doped (Ba_0.85Ca_0.15)(Ti_0.9Zr_0.1)_1−xMn_xO₃ (x = 0.000, 0.005, 0.010, 0.015, 0.100) (BCZTM) negative temperature coefficient (NTC) thermistor ceramics were prepared by solid-state method, and a research of their microstructures and electrical properties was also carried out. The excellent NTC properties of BCZTM ceramics sintered at high temperature were characterized by X-ray diffraction (XRD), scanning electron microscope, X-ray photoelectron spectroscopy, Raman spectroscopy, and infrared spectra (IR) analysis in this study. It is proved that the sintering temperature of BCZTM NTC thermistor ceramics is reduced by doping; it possesses a wide working temperature range (200–1100 °C) as well. All XRD, Raman, and IR spectra indicate the formation of perovskite phase. A trace Mn-doping can regulate the resistivity and activation energy of materials, yielding B_400/900 = 9992.1−11186.8 K, ρ₉₀₀ = 245.9−664.4 Ω cm, E_a600/900 = 0.9649–1.0175 eV, whereas excessive (x = 0.100) Mn-doping leads to a second phase. Besides, owing to small aging coefficient at 900 °C (less than 0.8%) and good high temperature stability, it can be used as a candidate material for high temperature and harsh environment.