High temperature Raman spectroscopy study on the microstructure of the boundary layer around a growing LiB3O5 crystal

High temperature Raman spectroscopy has been applied to investigate in situ the microstructure of the high temperature solution near a LiB3O5 (LBO) crystal–solution interface. A preordering boundary layer was found around the interface. In the boundary layer, an isomerization reaction between 3-coordinated and 4-coordinated boron was observed. The reaction led to the formation of B3Ø7 triborate groups, the characteristic structural group involved in the LBO crystal. According to the mechanism, the growth habits of LBO crystal can be understood well.