Magnetocaloric effect suppression induced by mechanical milling on intermetallic DyCO2.

Structural and magnetic properties of mechanically milled samples of intermetallic DyCo2 were investigated by x-ray diffraction and magnetization measurements. The results show that the average crystallite size is reduced down to 35 nm for the sample milled for 8 h. The milling process induces structural disorder as evidenced by x-ray diffraction data, leading to a weakening of Itinerant Electron Metamagnetism (IEM) mechanism and suppression of the magnetocaloric effect. The RCP values of milled samples were not significantly reduced in comparison with the bulk sample due to the broadening of magnetic entropy change peak.