Influence of non-magnetic Cu on structural, magnetic and magnetocaloric properties on NiMnIn bulk Heusler alloys.

• Ni 47 Mn 40-s Cu s In 13 alloys are prepared by an arc-melting method. • Structural properties are characterized by XRD, and SEM. • The Cu substitution in the Mn-site shifts Ms temperature to the low temperature side as e/a decrease. • Maxwell and Clausius-Clapeyron equations are used to estimate the values of magnetic entropy change. • A maximal ΔS M of 10 J.kg -1K−1 at a temperature of 248 K has been obtained in the s = 1 than ΔS M of 1.27 J.kg -1K−1 (s = 0). The structural, magnetic, and magnetocaloric characteristics of bulk Cu-doped Ni 47 Mn 40 -s Cu s In 13 Heusler alloys (s = 0 and 1) were investigated. Temperature-dependent magnetizations for Ni 47 Mn 40 -s Cu s In 13 (s = 0 and 1) were performed under a magnetic field (H) 0.05 T. The substitution of Copper (Cu) for Manganese (Mn) reduces the structural as well as magnetic phase transition temperatures. At room temperature (RT), PXRD pattern of Ni 47 Mn 40 -s Cu s In 13 (s = 0 and 1) bulk Heusler alloys shows that both samples have a cubic structure. The copper substitution in the Mn-site shifts the martensitic transformation temperature to the low temperature side as valence electron concentrations (e/a) decrease [M S = 288 K for s = 0 and M S = 251 K for s = 1]. The isothermal magnetization [M(H)] curve in the vicinity of the martensitic transition for s = 1 alloy exhibits the typical metamagnetic behavior that is not present for s = 0 Heusler alloys. The alloys reveal positive magnetic entropy changes (ΔS M) for s = 0 and 1 respectively. A maximal ΔS M of 10 J.kg -1K−1 at a temperature of 248 K has been obtained in the s = 1 compare than ΔS M of 1.27 J.kg -1K−1 (s = 0) alloys for a field change of 0–5 T. [ABSTRACT FROM AUTHOR]