BGO晶体生长固液边界层结构的微区研究

Analysis on Raman Spectra of Growth Solid-liquid Boundary Layer of BGO Crystal

研究了BGO晶体固/液边界层及其两侧晶体和熔体的高温拉曼光谱,分析了BGO晶体生长固/液边界层以及边界层两侧晶体和熔体的结构特征。结果显示,桥氧键Bi-O-Ge和O-Bi-O在晶体和边界层中都存在,而在熔体中消失。说明[GeO4]和[BiO6]结构基团在晶体及边界层中都存在,边界层中的结构已接近晶体结构;但在熔体中[GeO4]结构基团和Bi3+却是两种独立的存在,长程有序的晶体结构消失。并首次报道了BGO晶体固/液边界层的厚度约为50μm。

The high-temperature Raman spectra of the growth solid-liquid boundary layer of BGO crystal were studied. The structure characters in boundary layer, melts and crystal were analyzed. The results show that there exits [ GeO4 ] polyhedral structure and Bi ion independently in BGO melt. The bridge bonds Bi-O-Ge and O-Bi-O are present in both the crystal and boundary layer, but disappear in the melt. The structure of the growth solid-liquid boundary layer is similar to that of BGO crystal. In the melt, the long-range order structure of the crystal disappears. Finally, we obtained the thickness of the growth solid-liquid boundary layer of BGO crystal for first time, it is about 50μm.