Study of the K2Ni(SO4)2 ∙ 6H2O–K2Co(SO4)2 ∙ 6H2O–H2O diagram and determination of the conditions for growing K2(Ni,Co)(SO4)2 ∙ 6H2O mixed crystals

Abstract

The phase diagram of the K₂Ni(SO₄)₂ · 6H₂O–K₂Co(SO₄)₂ · 6H₂O–H₂O ternary system is investigated in the temperature range of 30–70°С, and a relationship between the compositions of the equilibrium phases of the K₂Co_xNi_(1–x)(SO₄)₂ · 6H₂O (KCNSH) solid solution and the growth solution is established. It is shown how the salt compositions of the liquid and solid phases change during crystal growth upon slow cooling of solution. A dependence of the lattice parameters of the KCNSH solid solution on the concentration of isomorphic components is experimentally found.