Magnetism and Mechanical Properties of Mn<sub>1.28</sub>Fe<sub>0.67</sub>P<sub>0.48</sub>Si<sub>0.52</sub> / Cu Composites

Abstract

This paper reports the effect of Cu doping in first order phase transition material Mn1.28Fe0.67P0.48Si0.52on its phase structure, magnetocaloric effect and mechanical properties. The results of XRD, SEM and EDS analysis show that the Mn1.28Fe0.67P0.48Si0.52in this composite forms Fe2P hexagonal structure and the space group is P-62m;Most of Cu exists as a simple substance, and a small amount of Cu and Mn form a solid solution. When the mass ratio of Cu reaches 10:4, the (Mn,Fe)3Si phase appears in Mn1.28Fe0.67P0.48Si0.52. The magnetic measurement results show that the saturation magnetization of Mn1.28Fe0.67P0.48Si0.52after Cu doping has no obvious change, the Curie temperature decreases, and the thermal hysteresis increases. The maximum magnetic entropy change becomes smaller as the Cu content increases. Under a 1.5 T external magnetic field, the maximum magnetic entropy ΔSmof the composite decreases rapidly from 11 J/kg·K atx= 0 to 4 J/kg·K atx= 5,the half width of the magnetic entropy change gradually increases. The Vickers hardness of the composite is reduced, the compressive strength has been greatly improved, and the mechanical properties have been significantly enhanced after Cu doping.