Characterization of Grain Boundaries of Lead-Free Semiconducting Ceramics Using BaTiO₃-(Bi_1/2K_1/2)TiO₃ System

Abstract:

BaTiO₃–(Bi_1/2K_1/2)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.

• Periodical: Key Engineering Materials (Volume 485)
• Pages: 241-244
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.485.241
• Online since: July 2011
• Authors: Hiroaki Takeda, Han Joong Sang, Takashi Tateishi, Spela Kunej, Colin Leach, Robert Freer, Takuya Hoshina, Takaaki Tsurumi
• Keywords: BaTiO₃, SEM Analysis, Semiconducting Ceramics, Thermistor, Titanate

References

[1] Titabari-kei Handotai, edited by E. Shuppan Iinkai (Giken, Tokyo, 1980) p.11 [in Japanese].

[2] G. Shirane, S. Hoshino, J. Phys. Soc. Jpn. Vol. 6 (1951), p.265.

[3] G. A. Smolensky, V. A. Isupov, A. I. Agranovskaya and N. N. Krainik, Sov. Phys. Solid. State Vol. 2 (1961), p.2651.

[4] C. F. Buhrer, J. Chem. Phys. Vol. 36 (1962), p.798.

[5] H. Takeda, W. Aoto and T. Shiosaki, Appl. Phys. Lett. Vol. 87 (2005) 102104.

[6] H. Takeda, T. Shimada, Y. Katsuyama, T. Shiosaki, J. Electroceram. Vol. 22 (2009), p.263.

[7] H. Takeda, H. Harinaka, T. Shiosaki, M. A. Zubar, C. Leach, R. Freer, T. Hoshina, T. Tsurumi, J. Eur. Ceram. Soc. Vol. 30 (2010), p.555.

[8] D. C. Sinclair and A. R. West, J. Appl. Phys. Vol. 66 (1989), p.3580.

[9] C. Leach, and J. D. Russell, J. Eur. Ceram. Soc. Vol. 15 (1995), p.617.

[10] O. Saburi and K. Wakino, IEEE Trans. Compon. Parts Vol. CP-10 (1963), p.53.

[11] P. -H. Xiang, H. Takeda, T. Shiosaki, J. Appl. Phys. Vol. 103 (2008) 064102.

[12] K. Hayashi, T. Yamamoto, Y. Ikuhara, T. Sakuma, J. Am. Ceram. Soc. Vol. 83 (2000), p.2684.

[13] J. Seaton, C. Leach, J. Eur. Ceram. Soc. Vol. 24 (2004), p.1191.

[14] W. Heywang, J. Mater. Sci. Vol. 6 (1971), p.1214.