1982 年 46 巻 11 号 p. 1055-1060
In a previous paper, the existence of octahedral coordinate Al3+ ion in the range of molar ratio of Al2O3/MO<1 was inferred from the effect of Al2O3 on the viscosities of Na2O, PbO, CaO and MnO silicate melts. In the present study, the viscosities of K2O, Li2O, BaO, ZnO, SrO and MgO systems were measured in order to confirm the previous result, and the viscosity data of each alumino-silicate melt were arranged using a parameter P corresponding to the ratio, nO−⁄nSi, in the binary silicate.
The parameter P is expressed by
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\ oindentwhere ZM is the electric charge of M ion, and nM, nSi and nAl are the ion fractions, and X is the ratio of the number of tetrahedral coordinate Al3+ ions to that of the total Al3+ ions.
Satisfactory results were obtained by the arrangement described above, and calculated values of X were 0.95(K2O), 0.90(Na2O, BaO), 0.78(SrO), 0.74(PbO), 0.73(Li2O, CaO), 0.60(MnO), 0.51(MgO) and 0.50(ZnO). Plot of X against the polarizing power Z⁄ri2 was linear, and X decreased with the basicity of MO.