Investigation of a BiB3O6crystal growth mechanism by high-temperature Raman spectroscopy

High-temperature Raman spectroscopy has been applied to investigate the melt structure near the BiB3O6 (BIBO) crystal–melt interface. Based on the experimental results, the crystal growth mechanism was proposed. (BOO)n (O = bridging oxygen atom) chains and free Bi3+ cations present in the BIBO bulk melt act as the crystal growth units. Bi-O bonds and [BO4]-tetrahedra were found near the BIBO crystal–melt interface. Two neighboring oxygen atoms in a (BOO)n chain or in two different (BOO)n chains are connected by the Bi3+ cations to form the structural prototype of BIBO crystal. Two adjacent (BOO)n chains are further connected to each other through the [BO4] tetrahedra to form the BIBO crystal structure. The predicted growth habit of the BIBO crystal is consistent with the observed one based on the mechanism.