New solid solutions of mixed alkali-zinc diphosphates LiNa1 − xKxZnP2O7

Phase relationships in the LiNaZnP2O7-LiKZnP2O7 system have been studied. For the first time a vast region of solid solutions of the rhombic syngony LiNa1 − x K x ZnP2O7 containing simultaneously three alkali cations was found. The miscibility is broken at the temperature of the polymorphous transformations LiKZnP2O7 (270°C) and below, with the formation of the two-phase region of the solid solution with the rhombic and monoclinic structures (0.85 ≤ x ≤ 1 at 25°C).