Some physical properties of YxHo1−xNi2 solid solutions

Polycrystalline samples of YxHo1-xNi2 solid solutions with 1 # > x # > 0 have been studied using X-ray diffraction analysis and magnetic, electrical resistivity, and heat capacity measurements. The X-ray diffraction performed at room temperature allowed us to reveal that the YxHo1-xNi2 solid solutions solidify with the formation of a Laves-phase superstructure corresponding to the space group F=43m; no Laves-phase structure is formed. At low temperatures, the YxHo1-xNi2 solid solutions with 0.6 # > x # > 0 are ferromagnets. Their Curie temperatures decrease linearly from 17.6 K for HoNi2 to 4.8 K for Y0.6Ho0.4Ni2. The compounds with x # > 0.8 and YNi2 do not show any long-range magnetic order. At high temperatures, all solid solutions are Curie-Weiss paramagnets. The temperature dependencies of the electrical resistivity were found to be typical of alloys exhibiting metallic conductivity. The Debye temperatures, phonon and conduction electron contributions as well as the magnetic part of heat capacity were determined from the heat capacity measurements. The magnetocaloric effect was estimated from measurements performed in a low magnetic field of 0.42 T.