1. Observation of colossal magnetocaloric effect and its dependence on applied hydrostatic pressure in thermally cycled Mn0.53Fe0.47NiSi0.53Ge0.47 alloy.
- Author
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Dutta, P., Pramanick, S., Chattopadhyay, S., Das, D., and Chatterjee, S.
- Subjects
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MAGNETOCALORIC effects , *SOLID solutions , *FERROMAGNETIC materials , *HYDROSTATIC pressure , *COLOSSAL magnetoresistance - Abstract
Magnetic and magnetocaloric properties of a solid solution of MnNiSi and FeNiGe alloys with nominal composition Mn 0.53 Fe 0.47 NiSi 0.53 Ge 0.47 have been investigated through dc magnetic measurements in ambient as well as in high pressure conditions. The alloy undergoes magneto-structural transition from the paramagnetic hexagonal Ni 2 In type structure to the ferromagnetic orthorhombic TiNiSi-type structure on cooling around 160 K. The alloy shows significant amount of training effect in magnetization when it is thermally cycled through the first order martensitic transition. We observe a colossal magnetocaloric effect (MCE) ( Δ S = −70.1 J/kg-K for H = 0–50 kOe) in ambient condition around the magneto-structural transition ( ∼ 176 K). Application of external hydrostatic pressure results in a significant decrease in the MCE value of the alloy. Reasonably large value of refrigeration capacity (RC) in ambient as well as in high pressure conditions (RC = 184.4 and 123 J/kg in ambient and 5 kbar of external pressure respectively) confirms its acceptance as a good magnetic refrigerant for practical uses. Metamagnetic behavior of the alloy around the magneto-structural transition presumably plays the key role towards the observation of such colossal value of MCE. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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