SURFACE TENSIONS AND DENSITIES OF MELTS IN TIO2-BAO AND TIO2-NA2O SYSTEMS

Surface tensions and densities of melts in the TiO2-BaO and TiO2-Na2O binary systems were measured by the maximum bubble pressure method accurately. The results obtained were as follows: (1) Surface tensions of melts in the TiO2-BaO binary system are in agreement with calculated values from Guggenheim's equation for ideal solution near the TiO2-50 mol%BaO composition, but for melts in the high TiO2 concentration region they deviate positively from calculated values for ideal solution. While for melts in the TiO2-Na2O binary system they deviate negatively from the calculated values for ideal solution. (2) Molar volumes of these two binary systems deviate positively from the additive rule on volume. (3) Molar volumes of molten MxO.TiO2(X=1 for M: Ti2+, Ba2+ and X=2 for M: Na+) near the melting point increase linearly as a function of Xr(c)3(r(c): the ionic radius of the cation M). (4) Surface tensions of molten MxO.TiO2 near the melting point increase as the ionic potentials of the cation M increase.