Magnetocaloric Effect of LaY0.1Fe11.4T0.1Si1.5(T= Cr, Mn, Fe, Co, Ni) Alloys

The LaY0.1Fe11.4T0.1Si1.5(T = Cr, Mn, Fe, Co, Ni) alloys were prepared by arc melting. XRD analysis and SEM component analysis show that the LaY0.1Fe11.4T0.1Si1.5(T = Cr, Mn, Fe, Co, Ni) alloys consist of the NaZn13-type cubic phase, minor amount of La-rich phase (P4/nmm) and alpha-Fe phase. The substitution for Fe site leads to lattice parameter of alloys decrease with decreasing of the atom radius of substitution atom T (except for T = Cr). Magnetic measurement indicates that the Curie temperature of the alloys increases with decreasing of the atom radius of substitution atom T (except for T = Mn). Magnetic entropy changes -Delta S-m were calculated from the isothermal magnetizations by the Maxwell relation. The maximum values of the magnetic entropy change are 5.1, 13.0, 20.7, 12.7 and 7.4 J.kg(-1).K-1, respectively. It should be noticed that the alloy has the largest magnetic entropy change for T = Fe. The largest value of magnetic entropy change extends to the high temperature zone when increasing the external fields, which is due to the IEMT above Criue temperature.