Regulation of Magnetic Phase Transition and Magnetocaloric Effect of DyCo2−xCrx Compounds

Abstract

The magnetic phase transition, magnetic and magnetocaloric effect of DyCo2−xCrx (x = 0.0–0.2) compounds have been studied. X‐ray diffraction (XRD) data show that the main phases of DyCo2−xCrx compounds are MgCu2‐type cubic crystal structure, and the maximum atomic concentration of Cr in DyCo2 is 5%. With the x changed from 0.0 to 0.2, both of the lattice parameter and cell volume increased, and the coercivity at 10 K increased from 890 to 2839 Oe. With the introduction of Cr atoms, the type of magnetic phase transition can be regulated from the first order to the second order. Under a 5 T magnetic field, the maximum magnetic entropy changes (ΔSM) of DyCo2−xCrx (x = 0.0, 0.1, and 0.2) compounds are 10.4, 8.4, and 6.8 J kg−1 K−1, respectively, but the relative cooling power (RCP) actually increases, with values of 290.6, 312.5, and 396.7 J kg−1 respectively, which is because the width at half‐maximum of the ΔSM peak (δTFWHM) is increased.