LiB3O 5晶体及其自助溶生长溶液的高温拉曼光谱研究

利用高温共焦激光显微拉曼光谱技术，研究了非线性光学晶体LiB3O5以及晶体自助溶生长溶液的高温微结构特征。通过对LiB3O5晶体高温拉曼光谱、Li2O?4B2O3组分玻璃体常温拉曼光谱和Li2O?4B2O3高温溶液拉曼光谱的分析表明：晶体、玻璃体中主要的结构单元为包含一个BØ4(Ø为桥氧)结构的硼氧六元环。随着温度的升高，该六元环中BØ4结构稳定性降低，发生硼氧四配位BØ4向三配位BØ3的转变。从而造成包含一个BØ4结构的硼氧六元环部分被破坏，Li2O?4B2O3高温溶液中硼氧六元环基团B3Ø6相对浓度增高。Li2O?4B2O3高温溶液这一微结构特征对形成LiB3O5晶体相是有利的。

Investigation on LiB3O5 crystal and its growing solutions using high temperature Raman spectroscopy

Using the high micro-Raman spectroscopy, the micro-structures of non-linear optical LiB3O5 crystal and the high temperature solution were studied. The high temperature Raman spectra of LiB3O5 crystals, Raman spectra of lithium borate glasses Li2O?4B2O3 at room temperature and its melt at high temperature were obtained. The analysis of these spectra indicates that the micro-structures of LiB3O5 crystal and lithium borate glasses Li2O?4B2O3 are mainly the six-number boroxol rings containing one BØ4 tetrahedron (Ø represents bridge oxygen). With the temperature increasing, the stability of the BØ4 tetrahedron decrease and destroys, a conversion from 4- coordinated boron BØ4 to 3- coordinated boron BØ3 occurs. As a result, the six-number boroxol rings containing one BØ4 are partly destroyed and the concentration of the boroxol B3Ø6 in the high temperature solution increases. The structural characteristics of the high temperature Li2O?4B2O3 solution are benefit for LiB3O5 crystal growth.