Magnetic Properties and Specific Heat of Laves Phase $Tb_{1-x}Sc_{x}Ni_2$ (x = 0.1, 0.2) Solid Solutions

Magnetic and specific heat measurements have been performed on polycrystalline $TbNi_2,$ $ScNi_2$ and their solid solutions $Tb_{1-x}Sc_{x}Ni_2$ (x = 0.1, 0.2). These compounds were synthesized using high-purity rare-earth metals. It has been found that the magnetic susceptibility of the nonmagnetic ScNi_2 compound exhibits a very weak temperature dependence characteristic of the Pauli paramagnets. $TbNi_2,$ $Tb_{0.9}Sc_{0.1}Ni_2$ and $Tb_{0.8}Sc_{0.2}Ni_2$ are typical Curie-Weiss paramagnets and are ferromagnetically ordered below 36 K. As revealed by room-temperature X-ray powder diffraction all the $Tb_{1-x}Sc_{x}Ni_2$ solid solutions have the cubic Laves C15-type superstructure. The Debye temperature, phonon and conduction electron contributions as well as the magnetic part of heat capacity were determined. The magnetocaloric effect has been studied by means of specific heat measurements in magnetic fields of 0.42 and 1 T. The effect of rare-earth substitution in $ScNi_2$ on the magnetic and magnetocaloric properties will be discussed.