Journal of Inorganic Materials ›› 2014, Vol. 29 ›› Issue (1): 91-97.DOI: 10.3724/SP.J.1077.2014.13303

• Research Paper • Previous Articles     Next Articles

Effect of Y Substitution on Electrical Properties of Yn(Ba0.8Bi0.2)1–nFe0.9Sn0.1O3 Negative Temperature Coefficient Thermistor Ceramics

YUAN Chang-Lai1, LUO Ying2, ZHOU Xiu-Juan1, YANG Yun1, CHEN Guo-Hua1, LIU Xin-Yu1   

  1. (1. School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China; 2. Guilin Academy of Air Force, Guilin 541004, China)
  • Received:2013-06-13 Revised:2013-09-02 Published:2014-01-20 Online:2013-12-09
  • Supported by:

    National Natural Science Foundation of China (51102055)

Abstract: Negative temperature coefficient thermistor ceramics based on Yn(Ba0.8Bi0.2)1–nFe0.9Sn0.1O3 were fabricated by conventional solid-state reaction techniques. Phases, microstructures, resistance-temperature curves and impedance characteristics of thermistor ceramics were characterized by X-ray diffraction, scanning electron microscope, resistance-temperature tester and ac impedance analyzer, respectively. Yn(Ba0.8Bi0.2)1–nFe0.9Sn0.1O3 thermistor ceramics with pseudo-cubic perovskite structure show average grain size of ~1.0 μm and the decreasing lattice parameter a with increase of Y content. Room-temperature resistivity, thermistor constant and activation energy of thermistor ceramics are in the range of 2.17–9.17 MΩ·cm, 6757–7171 K and 0.583–0.618 eV, respectively. When n = 0.02 and 0.04, the ceramic resistance is mainly attributed to the contribution of grain boundaries, grains and grain shells. Among them, the resistance value of grain is the highest one. However, for the ceramics with n = 0.06 and 0.08, the total resistance of thermistor ceramics is ascribed to the contribution of grain boundaries, domain walls and domains, and the domain regions show the larger resistance value than that of the other two elements. In the limited measured temperature range, all of grain boundaries, grain shells, grains, domain walls and domains show negative temperature coefficient thermistor behavior.

Key words: negative temperature coefficient thermistor ceramics, Yn(Ba0.8Bi0.2)1–nFe0.9Sn0.1O3, electrical properties, impedance analysis

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