Interferometric Study of the Stability of K2CoxNi(1−x)(SO4)2·6H2O (KCNSH) Mixed Crystal Faces Depending on the Composition and Flow Velocity of the Solution

The change in the surface morphology of the (001) and (110) faces of K2CoxNi(1−x)(SO4)2·6H2O (KCNSH) mixed crystal, depending on the supercooling solution, has been studied under various conditions by laser interferometry. The experiments were carried out in both static mode, by changing the solution composition, and in dynamic mode, by changing the flow velocity. The conditions for the onset and suppression of the reaction of the isomorphic replacement leading to the formation of mosaic micro-inhomogeneity in mixed crystals have been studied. The mechanism of the reaction of isomorphic replacement has been analyzed depending on the shift of the solution composition from the initial one. For the first time, it has been observed that the reaction of isomorphic replacement may occur through a layer-by-layer mechanism.