モル比M₂O₃ (M=Al, Ga)/MeO>1組成領域における珪酸塩中でのM₂O₃の挙動

抄録

The viscosities of Li₂O-SiO₂-Ga₂O₃ and BaO-SiO₂-Ga₂O₃ melts were measured in order to clarify the behaviour of M₂O₃ in the composition range of molar ratio M₂O₃/MeO>1, and the viscosity data on each gallosilicate were arranged using the parameter P_η(1) and P_η(2) corresponding to the composition ranges of molar ratio M₂O₃/MeO≤1 and M₂O₃/MeO≥1, respectively.
The parameter P_η(1) and P_η(2) are expressed by
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\ oindentwhere Z_Me is the electric charge of Me ion, n_i is the ion fraction of i ion, X_i^Ga is the ratio of tetrahedrally coordinated Ga³⁺ ions to the total Ga³⁺ ions and K_Ga is the correction factor to the X_i^Ga on the excess Ga₂O₃ to MeO in the case of molar ratio Ga₂O₃/MeO>1.
The viscosities measured in this study well explained by the parameters using K_Ga=0.56, X_Li^Ga=0.559 and X_Ba^Ga=0.54. The viscosities of the CaO-SiO₂-Al₂O₃ melts measured also showed a good relation to those calculated from the parameters using K_Al=0.73 and X_Ca^Al=0.63.