The influence of Er substitution on magnetic and magnetocaloric properties of Dy1−xErxCo2 solid solutions

Magnetic and heat capacity measurements have been carried out on polycrystalline Dy1−xErxCo2 solid solutions (0 ≤ x ≤ 0.3). Powder X-ray diffraction at room temperature revealed that all Dy1−xErxCo2 solid solutions consist of the C15 cubic Laves phase MgCu2 type structure. These solid solutions are ferromagnetic with a Curie temperature TC below 138 K. Their Curie temperatures decrease from 138 K for DyCo2 to 106 K for Dy0.7Er0.3Co2. At higher temperatures, all solid solutions are Curie–Weiss paramagnets. Both magnetic and heat capacity measurements showed that all samples undergo a first-order type phase transition at TC from paramagnetic to ferromagnetic state. Heat capacity measurements allowed us to determine the Debye temperature. The magnetocaloric effect has been estimated both in terms of isothermal magnetic entropy change and adiabatic temperature change in magnetic fields up to maximum 3 T.