Itinerant-electron metamagnetic transition and giant magnetocaloric effect in La0.8Ce0.2Fe11.4Si1.6 compound

Abstract

The itinerant-electron metamagnetic (IEM) transition and magnetocaloric effects (MCE’s) in the La0.8Ce0.2Fe13−xSix (x=1.6,1.4,1.2,1.0) compounds have been investigated by x-ray powder diffraction and magnetic measurements. The La0.8Ce0.2Fe11.4Si1.6 compound exhibits giant values of the isothermal magnetic entropy change ΔSM around the Curie temperature TC∼186K in low magnetic fields. The maximum value ∣ΔSM∣max∼78.29J∕kgK is under a field of 3T. Such large MCE’s are attributed to the sharp change of the magnetization, the field-induced IEM transition and a strong temperature dependence of the critical field BC. The substitution of Ce for part of La in La0.8Ce0.2Fe11.4Si1.6 increases the value of a(T)c(T)∕b(T)2 and enhances the property of IEM.