Preparation, heat capacity, magnetic properties, and the magnetocaloric effect of EuO

EuO was synthesized through the thermal reduction of Eu2O3 by a stoichiometric quantity of metallic Eu. According to the heat capacity and magnetic measurements, EuO undergoes a second-order phase transformation at ∼69K from the ferromagnetic to the paramagnetic state on heating. The magnetocaloric effect of EuO, both as the isothermal magnetic entropy change (ΔSmag) and the adiabatic temperature change (ΔTad), was obtained from the heat-capacity data. Also, the magnetization isotherms were used to calculate ΔSmag. EuO exhibits the magnetocaloric effect with a peak in the vicinity of the magnetic phase-transition temperature (∼69K), the amplitude of which is comparable to other known magnetocaloric materials. The ΔSmag calculated from the heat-capacity data is in excellent agreement with that calculated from the magnetization data.