Inverse magnetocaloric effect in Mn{sub 2}NiGa and Mn{sub 1.75}Ni{sub 1.25}Ga magnetic shape memory alloys

Journal Article · Mon Feb 03 04:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4863742· OSTI ID:22283300

Singh, Sanjay; Barman, S. R. ^[1]; Esakki Muthu, S.; Arumugam, S. ^[2]; Senyshyn, A. ^[3]; Rajput, P. ^[4]; Suard, E. ^[5]

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1. UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452001 (India)
2. Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli 620024 (India)
3. Forschungsneutronenquelle Heinz Maier-Leibnitz FRM-II, Technische Universität München, Lichtenbergstrasse 1, 85747 Garching b. München (Germany)
4. European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38000 Grenoble (France)
5. Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France)

Inverse magnetocaloric effect is demonstrated in Mn{sub 2}NiGa and Mn{sub 1.75}Ni{sub 1.25}Ga magnetic shape memory alloys. The entropy change at the martensite transition is larger in Mn{sub 1.75}Ni{sub 1.25}Ga, and it increases linearly with magnetic field in both the specimens. Existence of inverse magnetocaloric effect is consistent with the observation that magnetization in the martensite phase is smaller than the austenite phase. Although the Mn content is smaller in Mn{sub 1.75}Ni{sub 1.25}Ga, from neutron diffraction, we show that the origin of inverse magnetocaloric effect is the antiferromagnetic interaction between the Mn atoms occupying inequivalent sites.

• OSTI ID: 22283300
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 5 Vol. 104; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETISM
ATOMS
AUSTENITE
ENTROPY
GALLIUM ALLOYS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETIZATION
MANGANESE ALLOYS
MARTENSITE
NEUTRON DIFFRACTION
NICKEL ALLOYS
SHAPE MEMORY EFFECT