Glass formation and crystalline phases in the ternary systems CaO-Bi2O3-B2O3 and SrO-Bi2O3-B2O3

摘要

Large glass forming areas in the ternary systems CaO-Bi2O3-B2O3and SrO-Bi2O3-B2O3have been revealed by supercooling of melts. Transvarent glass samples have been obtained in a narrow bismuth-rich area of composition in the SrO-Bi2O3 system. Four pseudo-binary eutectic and four peritectic compositions have been revealed in the melting diagrams of the pseudo-binary systems Bi2O3-CaB2O4, BiBO3-CaB2O4, Bi2O3-SrB2O4, BiBO3-SrB2O4. The existence of ternary compounds CaBi2B2O7 and CaBi2B4O_(10) in the CaO-Bi2O3-B2O3 system, and SrBi2B2O7 and SrBi2B4O_(10) in the SrO-Bi2O3-B2O3 system has been confirmed. These compounds have good glass forming ability and are in the area of stable glasses. The melting behaviour of ternary compounds CaBi2B2O7, CaBi2B4O_(10), SrBi2B2O7, and SrBi2B4O_(10) has been studied. They melt incongruently at 770, 730, 755 and 790°C, respectively.