Specific Heat and Magnetocaloric Effect in Ho-Er-Co Solid Solutions

Specific heat measurements have been performed on polycrystalline HoCo₂, ErCo₂ and their solid solutions Ho_1?x Er _x Co₂ (0.1≤x≤0.5). These compounds were synthesized using high-purity rare-earth metals and cobalt. X-ray diffraction patterns taken at room temperature reveal that all compounds have the C15 cubic Laves phase structure. Heat capacity measurements have been performed in the temperature range of 2–300 K without magnetic field and in a magnetic field of 1 and 2 T. The magnetocaloric effect has been estimated in terms of isothermal magnetic entropy change for all solid solutions in magnetic fields up to 2 T. The effect of increasing Er amount in Ho_1?x Er _x Co₂ on the magnetic and magnetocaloric properties will be discussed.