Crystal structure, magnetic and electrical properties of M ' M2In (M '=Ti,Hf; M=Ni, Cu)

The intermetallic compounds HfCu2In, HfNi2In, TiCu2In and TiNi2In have been prepared and their crystal structure has been studied by X-ray diffraction . All these phases crystallize with the cubic MnCu2Al-type structure (space group Fm (3) over bar m), which is an ordered ternary derivative of the Bi F3-type structure. The structure of HfCu2In has been refined from the singl e-crystal X-ray data: a=6.351(1) Angstrom, R-F=0.0102, R-W=0.0235 for 74 un ique reflections hkl with F(hkl)>4 sigma(F). X-ray diffraction patterns of the compounds containing Cu revealed some homogeneity range extending along 25 at.% Hf or Ti. For HfCu2+xIn1-x, x=0.00-0.44, a=6.352-6.282(2) Angstrom ; for TiCu2+xIn1-x, x=0.00-0.44, a=6.228-6.115(2)degrees Angstrom. HfNi2In and TiNi2In exhibit a stoichiometric composition with a=6.2545(1) Angstrom and a=6.0982(1) Angstrom, respectively. Magnetic and electrical transport p roperties of HfNi2In, TiCu2In and TiNi2In have been studied in the range 1. 7-300 K. All these ternaries are Pauli paramagnets and metallic conductors. (C) 2000 Elsevier Science S.A. All rights reserved.