Muts N. Crystal structure of new multicomponent alumosilicides and alumogermanides of Pr (Tb) and d-elements Ni (Zr, Hf)

The isothermal cross-section of the phase diagram of the system PrNi2-PrAl2-PrGe2 in the PrGe2-rich region at 870 K was constructed based on X-ray phase, X-ray structural and local X-ray spectral analyses. The ternary Tb-Zr-Si and Tb-Hf-Si systems were investigated over the whole concentration range at 870 K. The homogenity ranges of the solid solutions based on binary and ternary compounds were determined. The crystal structures of the compounds Pr(Ni0.20Al0.30Ge0.50)1.8 and (Tb0.70Zr0.30)(Al0.17Si0.83) were determined from single crystal X-ray diffraction data by refinements in 5D- and 4D- space, respectively. The structural modulation is induced by the tendency of the different sorts of atom to form an ordered arrangement. Diagrams analysing the formation of different structural types RM and RM2 among intermetallic compounds (difference of the electronegativity versus the ratio of the atomic radii) are presented.