1. 1. T. Miya, Y. Terunuma, T. Hosaka and T. Miyashita, Rev. Electr. Commun. Lab., 27,497 (1979).
2. 2. T. Miya, M. Nakahara and N. Inagaki, Rev. Electr. Commun. Lab., 31,310 (1983).
3. 3. J. Wong, J. Non-Cryst. Solids, 20, 83 (1976).
4. 4. J. Wong and C. A. Angell, Glass Structure by Spectroscopy (Dekker, New York, 1976) pp.436.
5. 5. N. Shibata, M. Horiguchi and T. Edahiro, J. Non-Cryst. Solids, 45., 115 (1981).