1. For more details see P. McGeehin, J. Brit. Ceram. Soc. 80 (2), (1981), 37.
2. In this section we draw upon the unpublished work of K.T. Harrison.
3. W.L. Worrell, Ceramic Bull., 53 (1974), 425.
4. M. Gauthier, A. Belanger, Y. Meas and M. K1eitz in “Solid Electrolytes — General Principles, Characterization, Materials, Applications”, (P. Hagenmu11er and W. Van Gool, Eds.), p. 497, (1978), N.Y., Academic Press.
5. “Solid Electrolytes and Their Applications”, (E.C. Subbarao, Ed.,), (1980), N.Y., Plenum Press.