Characterization of Grain Boundaries of Lead-Free Semiconducting Ceramics Using BaTiO3-(Bi1/2K1/2)TiO3 System
BaTiO3–(Bi1/2K1/2)TiO3 (abbreviated as BT-BKT) solid solution ceramics, as a lead-free PTC (positive temperature coefficient of resistivity) thermistor material usable over 130°C, has been synthesized by sintering in N2 atmosphere and after annealing in air over 1200°C. In the BT-BKT ceramics with PTC property, the impedance/modulus spectroscopic plots have revealed that a third resistance-capacitance (RC) response besides grains and grain boundaries. Using the remote electron beam induced current (REBIC) configuration, imaging has revealed EBIC contrast consistent with the presence of negatively charged electrostatic grain boundary barriers in the BT-BKT semiconducting ceramics.
Chazono Hirokazu, Fujihara Shinobu, Katayama Keiichi, Masumoto Hiroshi, Mizoguchi Teruyasu, Osada Minoru, Shinozaki Kazuo and Takeda Hiroaki
H. Takeda et al., "Characterization of Grain Boundaries of Lead-Free Semiconducting Ceramics Using BaTiO3-(Bi1/2K1/2)TiO3 System", Key Engineering Materials, Vol. 485, pp. 241-244, 2011