The dependence of the solubility of NiCoSO·6HO (x = 0–1) on the composition of the solution at a temperature of 45°C was obtained. It has been established that an increase in temperature leads to a shift in the point of non-invariant equilibrium of the tetragonal and monoclinic phases towards a higher concentration of cobalt in solution. A thermogravimetric study has shown that as the Co content in the crystal increases, its thermal stability decreases. The spectral characteristics of crystals of different compositions have shown that the crystal can be used as a UV filter. The habitus of a NiCoSO·6HO monoclinic crystal obtained from a solution of the composition NiSO : CoSO = 50 : 50 wt. % has been determined.
Elena B. Rudneva (Wed,) studied this question.