Аңдатпа
The solubility diagram of the ternary system GdCl3–TbCl3–H2O is studied by means of isothermal saturation in ampules at 25°С. A continuous series of solid solutions of isovalent substitution crystallizes in the system $${\text{G}}{{{\text{d}}}_{x}}{\text{T}}{{{\text{b}}}_{{1 - x}}}{\text{C}}{{{\text{l}}}_{3}}{\kern 1pt} \cdot \,6{{{\text{H}}}_{2}}{\text{O}}.$$ The diagram of solubility in the three-component system GdCl3–TbCl3–H2O at 25°C is calculated according to the classical Pitzer model. Results from experiments agree convincingly with ones from thermodynamic modeling.