1969 年 38 巻 10 号 p. 928-936
Single crystals of optically good quality KTaxNb(1-x)O3(KTN), 10mm×10mm×15mm in size, are prepared by a modified Kyropoulos technique from melts which contain excess of K2CO3. The as-grown crystals possess well-developed (100) surfaces. When K2CO3 content is chosen to be 52_??_55 mol %, colorless and transparent crystals are grown and their resistivity ρ is as high as 1013Ω·cm. However, with increasing K2CO3 contents over 60 mole %, values of ρ decrease to 108Ω·cm and crystals become blue in color. Dielectric constant at Curie temperature Tc and Curie-Weiss constant are independent of K2CO3 content. Half-wave voltage Vπ are measured for several samples at temperatures about 10°C above the Tc. The value of Vπ, is about 300 V, which remains constant with K2CO3 content.