1. S. Nomura, K. Toyama, and K. Kaneta, Jpn. J. Appl. Phys. Part 2, 21, L642 (1982).
2. R. Guo, A.S. Shalla, and L.E. Cross, J. Appl. Phys., 75, 470 (1994).
3. S. Nomura, T. Konoike, Y. Sakabe, and K. Wakino, J. Am. Ceram. Soc., 67, 59 (1984).
4. F.S. Galasso, Structure, Properties and Preparation of Perovskite-Type Compounds (Pergamon, Oxford, 1969), pp. 13?15, 55.
5. H. Tamura, D.A. Sagala, and K. Wakino, Jpn. J. Appl. Phys. Part 1, 25, 787 (1986).