The change of CaKα due to chemical state was presented. From the results of measurements using a high resolution X-ray fluorescence spectrometer, it was found that CaKα₁ shifted to the lower energy side corresponding to the increase in the electronegativity of the nearest neighbor atoms. This result was reproduced by the theoretical calculation with a free atom model using SCC-DV-X_α method. From the measurements of polymorphic compounds and other Ca oxide compounds, it was found that CaKα₁ showed a tendency to shift to the higher energy side corresponding to the increase in the number of coordination and electronegativity of the next nearest neighbor atoms.

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This study was concerned with the formation of antimony spinels in the ternary systems of ZnO-CoO-Sb₂O₅, ZnO-NiO-Sb₂O₅, ZnO-MgO-Sb₂O₅, CoO-NiO-Sb₂O₅ and CoO-MgO-Sb₂O₅, and in the quaternary systems of ZnO-CoO-MgO-Sb₂O₅, CoO-MgO-NiO-Sb₂O₅, CoO-ZnO-NiO-Sb₂O₅ and ZnO-MgO-NiO-Sb₂O₅. Zn₇Sb₂O₁₂ and Co₇Sb₂O₁₂ are listed as spinel. On the other hand, spinels with the composition of Ni₇Sb₂O₁₂ and Mg₇Sb₂O₁₂ do not exist. Specimens were prepared by calcining the mixtures of each oxide of zinc and antimony, and basic carbonates of cobalt, nickel and magnesium at 1350°C for 1h. The formation of spinel solid solution was examined by X-ray diffraction, and the lattice parameter of each solid solution was calculated. The color was discussed by measuring the spectral reflectance. The results were summarized as follows.
1) Continuous solid solutions were obtained between Zn₇Sb₂O₁₂ and Co₇Sb₂O₁₂, and as the amount of Co²⁺ increased, the colors ranging from pale yellow green through brown to dark gray developed.
2) The incorporations of Ni²⁺ and Mg²⁺ into Zn₇Sb₂O₁₂ succeeded up to x=4.75 and 3.75 in Zn_7-xNi(Mg)_xSb₂O₁₂, respectively. As the amount of Ni²⁺ increased, the color changed from dull yellow through dark yellow to grayish brown.
3) The incorporations of Ni²⁺ and Mg²⁺ into Co₇Sb₂O₁₂ succeeded up to x=4 and x=4.5 in Co_7-xNi(Mg)_xSb₂O₁₂, respectively. An increase of Ni²⁺ caused the color to change from dark gray to dark bluish gray, and on the other hand, as the amount of Mg²⁺ increased, the color changed from dark gray to dark grayish green.
4) Continuous solid solutions were obtained between Zn₃Ni₄Sb₂O₁₂ and Co₃Ni₄Sb₂O₁₂. An increase of Co²⁺ in this system, yielded the colors ranging from grayish brown to dark greenish gray.
5) Between Co₃Ni₄Sb₂O₁₂ and Co₃Mg₄Sb₂O₁₂, continuous solid solutions were also obtained. As the amount of Mg²⁺ increased, the color changed from dark bluish gray through dark greenish gray to dark green.
6) The incorporation of Mg²⁺ into Zn₃Ni₄Sb₂O₁₂ succeeded up to x=3.5 in Zn₃Ni_4-xMg_xSb₂O₁₂. As the amount of Mg²⁺ increased in this system, the colors ranging from brown through dull yellow to pale yellow green developed.

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Highly conductive ceramic composites with high mechanical strength and high resistance to oxidation have been developed from electro-conductive high temperature materials and SiC. SiC powder and one from TiC, ZrC, WC, ZrB₂, TiB₂, HfB₂, NbB₂, TaB₂ and TiN powders were mixed in the volume ratio of 1:1 and hot-pressed, Sintered composites have electrical resistivity of the order of 10^-4Ω·cm at room temperature, which is comparable to the values of the Ni-Cr heating material. Their flexural strength values are from half to nearly equal to the value of SiC alone. The composites of SiC with one of ZrB₂, TiB₂, HfB₂ and TaB₂ have higher resistance to oxidation than the others. Their increase in weight by oxidation in the air at 1100°C for 100h holding is as small as that of the most resistant metal to oxidation, Co-32% Cr alloy. Sintered composites are composed of grains of SiC and high temperature materials dispersed in each other. The electrical resistivity of the composites is about four times as high as that of the high temperature materials components, following the conduction model for a homogeneous mixture of two kinds of particles with different conductivity. Propagation of oxidation into the materials is suppressed near the surface of the composites.

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The subsolidus phase relations in the system SrF₂-LaF₃ were studied between 1400°C and 500°C by solid state and hydrothermal reactions. Starting samples were (1) mixed and (2) fired samples of 99.9% SrF₂ and 99.9% LaF₃ powders. The fired samples were prepared by firing the mixed samples (1) at 1300°C for 4h in Ar. The mixed samples attained equilibrium state by heating at 1400°C in a Pt capsule for 4h and at 1000°C, 750°C for (4+4=8) h, (7+7+9=23) days respectively in a quartz glass ampule by solid state reaction. At 750°C, 650°C and 500°C, these samples, (1) and (2), were treated under hydrothermal conditions of 100MPa for 1-30 days to accelerate the reaction between SrF₂ and LaF₃ using distilled water or an aqueous solution of alkaline metal (Li, Na and K) fluorides, chlorides, bromides, carbonates, nitrates, sulfates or hydroxides as a mineralizer. An aqueous solution of LiCl was the best mineralizer for the system studied. After completion of the heating run, the samples were quenched into cold water. The phase equilibria were confirmed because the same lattice parameter was observed in the products from both samples of (1) and (2) treated hydrothermally at the same temperature for a long time regardless of the mineralizers. It took 1, 1 and 30 days to attain the equilibria at 750° 650° and 500°C respectively. The lattice parameter of products treated at 750°C by solid state or hydrothermal reactions resulted in the coincidence in both cases. At any temperatures, a linear relation could be obtained between the composition and the lattice parameter of the solid solutions of each phase (SrF₂ s.s. and LaF₃ s.s.) corresponding to the Vegard's law. The solubility limits in SrF₂ s.s. were determined to be 48, 48, 47, 47 and 46mol% LaF₃, and those in LaF₃ s.s. to be 15, 10, 6, 4, and 2mol% SrF₂ (all deviation; ±1mol%) at 1400°, 1000°, 750°, 650°, and 500°C respectively. These phase boundaries consist with the liquidus and solidus reported previously. A phase diagram was constructed according to these data.

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Porous glass prepared by acid leaching of phase-separated sodium borosilicate glass usually contains colloidal silica which originates from the silica component in the borate phase. In order to prevent the precipitation of colloidal silica, molybdenum trioxide was added to sodium borosilicate glasses and its effect on the pore characteristics was studied. The effect of heat-treatment temperature of the starting glass was also examined. With increasing heat-treatment temperature, the pores of skeleton which correspond to the phase-separated structure coarsened and the colloidal silica increased. The colloidal silica was reduced by annealing the phase-separated glass. The addition of molybdenum trioxide promoted the phase separation of starting glasses and diminished the colloidal silica. The effect of molybdenum oxide was ascribed to the lowering of silica concentration in the borate phase and to the formation of water-soluble complex with silica during the leaching. Molybdenum ions showed a tendency to be reduced to lower valence states during glass melting. A molybdenum-containing glass melted under moderate reducing condition exhibited a maximum value in the pore radius of skeleton and a minimum value in the pore volumes of skeleton and colloidal silica.

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The influence of residual stresses on the relationship between fracture patterns and fracture stresses was examined for annealed float glasses, semi-tempered and fully-tempered glasses. Fracture stresses were measured in Ring on Ring or four-point bending tests, using specimens with artificial surface flaws produced by a micro-hardness tester with a Vickers indenter. The fracture mirror sizes were defined as one half of surface length and a depth of a fracture mirror for annealed and tempered glasses, respectively. They were measured by using an optical microscope. A generalized mirror equation on the relationship between a fracture stress and a mirror size was proposed by considering the fracture mechanics. In this equation, the value of 1.88MPa·m^1/2 was obtained as a mirror constant calculated from the experimental correlations between fracture stresses and mirror sizes. It was also found that the mirror constant is independent of the degree of residual stresses. Fracture mirror boundary patterns observed in bending tests were also accurately described by using the mirror equation which was incorporated with both the applied stress and the residual stress for each glass thickness.

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