Shuzo Hasegawa

Growth of Strontium Titanate Single Crystals from Molten Salts

Single crystals of strontium titanate (SrTiO3) were grown by flux method. The best results were obtained with KF-LiF and KF-K2MoO4 flux systems. Reasonably large single crystals were yielded from the solvent of KF-LiF systems and fine small crystals which were colorless, transparent and flawless were obtained from KF-K2MoO4 systems. The experiments were carried out by slow cooling method, temperature of growth being 1250°C and cooling rate 2–5°C/hr. The single crystals obtained were 4 mm in size on an average and larger ones 7 mm across. The crystal habits were all cubic in form.

Titanite from a pegmatite at Ishikawa Town, Fukushima Prefecture

Titanite from pegmatite deposit is very rare in Japan, The writers found the mineral in a pegmatite at Ishikawa Town. Essential minerals of the pegmatite are quartz and perthite. Titanite occurs in perthite at a marginal parts of the pegmatite as a crystalline aggregate measuring up to 2 ?? 3cm. The specific gravity determined by a pycnometer is G15 ?? 4=3.510. Color is grayish yellow in thin section and its pleochroism is weak. The result of chemical anaylsis is given as follows. SiO2 30.65, TiO2 37.64, Al2O3 2.95, Fe2O3 0.71, [Y] 2O3 none, FeO none, MnO 0.10, CaO 27.05, MgO none, Ig. loss 0.45, Total 99.55.%. From the calculation of molecular proportion, it may be obvious that the mineral contain 7.7% R2SiO5 (R=Al, Fe) in CaTiSiO5.