原位受控晶化法制备BiBO_3晶体的析晶动力学

Crystallization Kinetics of BiBO_3 Crystal by In-Situ Crystallization

采用熔融冷淬法制备了Bi_2O_3-B_2O_3(30 mol%≤Bi_2O_3≤60 mol%)二元系统玻璃。运用非等温DSC分析以及Satava和Ozawa-Chen方法研究了Bi_2O_3-B_2O_3玻璃的非等温析晶特性,并计算了玻璃的析晶动力学参数。结果表明,在50 mol%≤Bi_2O_3≤60 mol%范围内,玻璃晶化热处理后可析出针状BiBO_3晶体,是原位受控晶化法制备BiBO_3晶体的最佳组成范围。添加La_2O_3和Sm_2O_3,有助于抑制高聚合度的铋硼酸盐晶体的析出,促进BiBO_3晶体的形成;而添加Yb_2O_3的铋硼酸盐玻璃,晶化热处理后以颗粒状的Bi_6B_(10)O_(24)晶体为主,不利于BiBO_3晶体的析出。对稀土掺杂铋硼酸盐玻璃样品在460～540℃间热处理5 h,可获得表面析晶的透明玻璃样品。

Bi2O3-B2O3 glass containing 30-60 mol% Bi2O3 were prepared by the melting-quenching method. The crystallization kinetics of Bi2O3-B2O3 glasses were studied by DSC, Satava and Ozawa-Chen methods. The results showed that needle BiBO3 crystal could be formed by re-heated process in the range of 50 mol%≤ Bi2O3≤ 60 mol%. La2O3 and Sm2O3 restrained the separation of high-polymerized bismuth borate crystals and promoted to form BiBO3 crystal. After reheated, the main crystal of Yb2O3 doped bismuth borate glass appeared as the grain-like Bi6B10O24 crystal. This indicated that Yb2O3 was not proper for the separation of BiBO3 crystal. Transparent surface-crystallized rare-earth doped bismuth borate glasses were obtained by reheating the ceramics between 460～540℃ for 5 h.