Magnetic phase transition and magnetic entropy change in (Dy1−xRx)Co2, where R=La and Sm, compounds

Magnetization properties were measured for a series of Dy1−xSmxCo2 and Dy1−xLaxCo2 compounds. It was found that the magnetization lowers when the Dy content decreases in the compounds. In both systems, a metamagnetic transition and first-order magnetic phase transition is observed for certain ranges of the Dy content, and gradually weakens until it disappears as the content of Dy decreases. The magnetic entropy changes |ΔSm|, as a function of the temperature in the magnetic field of 1 T for both series of compounds, have been calculated. Although the |ΔSm| decreases with the decrease of Dy, it does remain fairly large within a certain range of the Dy content. The curie temperature can be adjusted by adjusting x, which indicates that the (Dy1−xRx)Co2 (R=Sm, La) compounds may have potential applications as magnetic refrigerants.