Interface kinetics and crystal growth mechanism of a new organometallic coordination compound: Triallylthiourea mercury bromide

Interface kinetics processes of ATMB crystal have been investigated in real time by using phase-contrast differential interferometric micrography with an automatic image-analysis system. The movement of straight steps on {1 0 1 2} faces have been studied. Experiment demonstrates that the mechanism of ATMB crystal growth is a typical model of multiple two-dimensional nucleation. During the crystal growth, there exist a critical supersaturation σ_*≅3-4%. When σ_* < σ < σ_** = 16.5%, crystals grow by the consecutive deposition of layers. If σ_** < σ < 18.50%, crystals grow by quasi-normal growth mechanism. The conditions of rapid growth of large ATMB crystal with good quality are presented.