Influence of Cu on the Magnetic Properties of La0.7Ce0.3Fe11.54-xCuxMn0.16Si1.3 Alloy and its Hydride

Abstract:

La(Fe, Si)₁₃ alloys exhibit first order magnetic transition showing large magnetocaloric effect, and is considered as a magnetocaloric effect material with the great applied prospect. La_0.7Ce_0.3Fe_11.54-xCu_xMn_0.16Si_1.3(x=0, 0.05, 0.1, 0.15)alloys with different proportion of Cu were prepared by high frequence induction melting furnace. With the aid of powder XRD and scanning electron microscope (SEM), the phase composition and microstructure were investigated. The magnetic properties were measured by using VersaLab. Curie temperature increases after partial substitution Cu for Fe, however an opposite result is obtained after hydrogenation. Although the magnetocaloric effects decrease with the increase of Cu content, the max magnetic entropy change of La_0.7Ce_0.3Fe_11.44Cu_0.1Mn_0.16Si_1.3H_1.68alloy is still as high as 8.5 J/kg.K(0 ~ 2 T), the relative cooling capacity improved (118 J/kg) and the hysteresis decrease evidently.

Key words:magnetocaloric effect; magnetic refrigeration; relative cooling capacity; hysteresis