HABIT AND FORMATION MECHANISM OF BETA-BAB2O4 CRYSTAL

The relationship between the orientation of structure unit [B3O6](3-) anion ring and the morphology of beta-BaB2O4 crystal has been studied on the basis of crystallography. According to the results measured fro m the solution structure of Na2O-B2O3 system the structure of the grow th unit of beta-BaB2O4 crystal and the incorporation discipline of the growth unit on the faces and facets of the crystal are proposed. The formation mechanism and crystallization habit of the beta-BaB2O4 are d iscussed. The dimensions of the growth unit vary with the physicochemi stry conditions of the crystal growth. Moreover, the incorporation rat es of the growth units with different dimensions on the faces and face ts are also changed. This is the major reason of the diversity of the crystal morphology.