System K2O Research Articles

Influence of TiO2 on Properties of Glasses in the System K2O–PbO–SiO2–TiO2 and Its Relation to Structure

By a progressive weight percent substitution of TiO2 for SiO2 at various rations of concentration of K2O and PbO, the entire region of glass formation in the quaternary system K2O–PbO–SiO2–TiO2 was covered with 51 glass compositions. The properties of these glasses were determined and studied with respect to the role of TiO2 in the system. The results indicated that the dielectric constant increased progressively with increasing TiO2 concentration whereas the dissipation factor showed an overall decrease, when measured at 1 Mc and 25°C. Density and the refractive index increased progressively with increasing TiO2 concentration but deviated from the additive relation. Chemical durability, expansivity, and softening temperature vs. composition curves showed definite inflections. The effect of TiO2 on oxygen packing indicated that Ti4+ strengthens the network in lower concentrations and weakens the network in higher concentrations in this system. It appears to be likely that Ti4+ changes its coordination number form 4 to 6.

Reactions of the Group VB Pentoxides with Alkali Oxides and Carbonates. III. Thermal and X-Ray Phase Diagrams of the System K2O or K2CO3 with Ta2O5

Reactions of the Group VB Pentoxides with Alkali Oxides and Carbonates. III. Thermal and X-Ray Phase Diagrams of the System K₂O or K₂CO₃ with Ta₂O₅

溶融スラツグの電氣化學的研究(I)

Up to this time, the potential measurment of molten slags was scarcely performed in comparison with that of the viscosity and electrical conductivity. In this paper, the author measured potentials in the binary systems K2O, Na2O, BaO, CaO-SiO2 making use of the C-SiC electrode couple with the object of determination of activities of the constituents. As the result, it was clear that the systems K2O, Na2O-SiO2; BaO-SiO2; CaO-SiO2 had some characteristics both in the magnitude and polarity of potential. This fact was due to the substantial difference in the construction of these systems.Moreover, the next relations were proved to be established between the activities aSiO2 aCaO of these slags and potentials, where E, E': measured e.m.f., Eo, Eo': standard e.m.f., m, m': molar numbers of constituents, n, n': numbers of electron, R: gas constant, T: absolute temperature, F: Faraday's constant.The author suggested that asio2 or aCaO could be derived from the measurement of the decomposition voltages and this potential values.