Near room temperature magnetocaloric properties in Ni deficient (Mn0.525Fe0.5)Ni0.975Si0.95Al0.05

Abstract

We present an experimental study on the crystalline, magnetic, and magnetocaloric properties of Ni deficient (Mn-rich) (Mn0.525Fe0.5)Ni0.975Si0.95Al0.05. The study has been performed by x-ray diffraction, scanning electron microscopy, and dc magnetization measurements. X-ray diffraction measurements showed that the sample primarily exhibited the orthorhombic structure at room temperature. The coupled structural and ferromagnetic transition occurred at ∼338 K, which is significantly larger than ∼320 K observed in (Mn0.50Fe0.5)NiSi0.95Al0.05. Maximum magnetic entropy changes of ΔSM = −9.5 and 25 J kg−1K−1 for ΔH = 20 kOe and 50 kOe, respectively, have been observed in the material. Large refrigeration capacities of 60 J/kg and 160 J/kg for field changes of ΔH = 20 kOe and 50 kOe, respectively, have also been observed.