Abstract:
The effects of V addition on the structural, magnetic, and magnetocaloric properties in Ni49-xVxMn37Sn12B2 (x = 0, 1, 2, and 3) alloys were investigated. XRD analyses performed at room temperature showed that the main sample was in martensite phase, while x = 3 sample was in L21 structure which is attributed to austenite phase. The samples exhibited a first-order structural transformation from austenite phase to martensite phase. The martensitic transformation (MT) temperature was reduced by increasing the amount of V. Besides, V doping caused an increase in magnetization. Although antiferromagnetic interactions arising from Mn–Mn couplings were effective at low temperatures, they vanished above the blocking temperature. Magnetic entropy change (ΔSM) of the samples was estimated using the Maxwell equation from isothermal magnetization curves. An inverse magnetocaloric effect was observed around the MT interval and ΔSM was significantly improved with increasing V content and applied magnetic field. Maximum refrigerant capacity (RC), which is one of the quality parameters for characterizing a magnetic refrigerant, was determined as 96.7 J/kg for x = 3 samples (ΔH = 5 T). © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.