Grain-Size Effect on the Magnetocaloric Properties of the $DyCo_{3}B_{2}$ Compound

The compound $DyCo_{3}B_{2}$ has been recently found to show a significant magnetocaloric effect (MCE) at the ferromagnetic ordering temperature $T_{C}$=22 K. In the present study we verify the influence of the mechanical milling, i.e. the grains size effect on the characteristic parameters describing MCE. The grain size has been determined after each milling time by X-ray diffraction. MCE has been extracted from both the isothermal magnetization and the specific heat measurements. It is found that even a long milling does not spoil significantly the MCE parameters and only $t_{m}$>5 h reduces noticeably the value of the magnetic susceptibility, the isothermal magnetic entropy change and the relative cooling power.