The magnetic phase transition, magnetic and magnetocaloric effect of DyCo_2−xCr_x (x = 0.0–0.2) compounds have been studied. X‐ray diffraction (XRD) data show that the main phases of DyCo_2−xCr_x 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 (ΔS_M) of DyCo_2−xCr_x (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 ΔS_M peak (δT_FWHM) is increased.

中文翻译：

---

DyCo2-xCrx化合物的磁性相变和磁热效应的调节

研究了DyCo _{2− x} Cr _x（x  = 0.0–0.2）化合物的磁性相变，磁性和磁热效应。X射线衍射（XRD）数据表明DyCo _{2− x} Cr _x化合物的主要相为MgCu ₂型立方晶体结构，DyCo ₂中Cr的最大原子浓度为5％。与x从0.0变为0.2，晶格参数和晶胞体积均增加，并且在10 K时的矫顽力从890 Oe增加到2839 Oe。随着Cr原子的引入，可以将磁性相变的类型从一阶调节到二阶。在5 T磁场下，DyCo _{2− x} Cr _x（x  = 0.0、0.1和0.2）化合物的最大磁熵变（ΔS _M）为10.4、8.4和6.8 J kg ^-1  K ^-1，但是，相对冷却功率（RCP）实际上增加了，分别为290.6、312.5和396.7 J kg ^-1，这是因为ΔS _M的一半最大宽度峰（δT _FWHM）增加。