Eu2O3-HI-H2O and EuI3-HI-H2O Systems at 25°C

Phase equilibria in the Eu2O3-HI-H2O and EuI3-HI-H2O systems at 25°C are studied by the solubility method. The fields of crystallization of europium triiodide nonahydrate EuI3 · 9H2O and basic iodide Eu2I(OH)5 · 2H2O are established. The crystal hydrates are characterized by X-ray powder diffraction, thermogravimetry, and crystal optics.