The effect of Mn substitution in LaFe11.7Si1.3compound on the magnetic properties and magnetic entropy changes

The magnetic properties and magnetic entropy changes of La(Fe 1− x Mn x ) 11.7 Si 1.3 ( x = 0–0.03) have been studied. The Curie temperatures T C decrease monotonously with increasing Mn concentration from 188 to 127 K, and the saturation magnetization μ S decreases from 23.9 μ B /fu to 22.2 μ B /fu respectively, as x increases from 0 to 0.03. The maximal magnetic entropy changes |Δ S |, under a magnetic field change of 0–5 T, are 26.0 J kg −1 K −1 , 25.7 J kg −1 K −1 , 20.8 J kg −1 K −1 and 17.1 J kg −1 K −1 for x = 0, 0.01, 0.02 and 0.03, respectively. The appearance of negative slopes in the Arrott plots for all samples confirms the occurrence of a first-order field-induced itinerant-electron metamagnetic (IEM) transition. Furthermore, the full-width at half-maximum (FWHM) of |Δ S | peak, δ T FWHM , increases obviously with increasing Mn content, which results in the decrease of the maximum magnetic entropy change.