The Influence of Supercooling and Hydrodynamics on the Mosaic and Radial Inhomogeneity of K₂Ni_XCo_(1–X)(SO₄)₂·6H₂O Mixed Crystal

Abstract

The mosaic and radial inhomogeneity of shaped mixed crystals of K2NixCo(1–x)(SO4)2·6H2O (KCNSH) were studied depending on the supercooling of solution, its velocity and its method of supply into the shaper. It was shown that mosaic inhomogeneity could be suppressed when solution is supercooled to about 2 °C. Peripheral supply of the solution (tangential to the wall of the shaper to create a “swirling” flow) with a rate of 55–135 cm/s provides better composition uniformity along the crystal surface in comparison with upright supply of the solution (flow is perpendicular to the crystal surface).

Keywords

• solution crystal growth
• mixed crystals
• mosaic inhomogeneity
• isomorphous replacement
• radial inhomogeneity