SOLID SOLUTIONS IN THE RNiIn–RNiGa (R = Pr, Ho) SYSTEMS

The PrNiIn–PrNiGa and HoNiIn–HoNiGa systems were investigated by X-ray powder diffraction and energy dispersive X-ray analysis in full concentration ranges at 870 K. The existence of two limited solid solutions in each system was observed and changes of unit cells parameters of the phases in them were determined. The crystal structure of PrNiIn0.79Ga0.21 phase was refined based on the experimental hkl reflections using the FullProf package: ZrNiAl-type structure, space group P-62m, Pearson symbol hP9, a = 0.74795(15), c = 0.39454(8) nm, RBragg = 0.077, Rf = 0.085. Partial substitution of indium by gallium atoms was confirmed by structure refinement from single crystal X-ray diffraction data: HoNiIn0.69Ga0.31 phase crystallizes with ZrNiAl-type structure (P-62m, hP9, a = 0.73604(3), c = 0.37241(2) nm, R1 = 0.0096 for 205 F2 values, 16 variables).