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Title: Anti-site disorder and improved functionality of Mn₂NiX (X = Al, Ga, In, Sn) inverse Heusler alloys

Recent first-principles calculations have predicted Mn₂NiX (X = Al, Ga, In, Sn) alloys to be magnetic shape memory alloys. Moreover, experiments on Mn₂NiGa and Mn₂NiSn suggest that the alloys deviate from the perfect inverse Heusler arrangement and that there is chemical disorder at the sublattices with tetrahedral symmetry. In this work, we investigate the effects of such chemical disorder on phase stabilities and magnetic properties using first-principles electronic structure methods. We find that except Mn₂NiAl, all other alloys show signatures of martensitic transformations in presence of anti-site disorder at the sublattices with tetrahedral symmetry. This improves the possibilities of realizing martensitic transformations at relatively low fields and the possibilities of obtaining significantly large inverse magneto-caloric effects, in comparison to perfect inverse Heusler arrangement of atoms. We analyze the origin of such improvements in functional properties by investigating electronic structures and magnetic exchange interactions.
Authors:
; ;  [1] ;  [2]
  1. Department of Physics, Indian Institute of Technology Guwahati, Guwahati, Assam 781039 (India)
  2. Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala (Sweden)
Publication Date:
OSTI Identifier:
22305757
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM COMPOUNDS; ELECTRONIC STRUCTURE; EXCHANGE INTERACTIONS; GALLIUM COMPOUNDS; HEUSLER ALLOYS; INDIUM COMPOUNDS; MAGNETIC PROPERTIES; MANGANESE COMPOUNDS; NICKEL COMPOUNDS; PHASE STABILITY; PHASE TRANSFORMATIONS; SHAPE MEMORY EFFECT; SIMULATION; SYMMETRY; TERNARY ALLOY SYSTEMS; TIN COMPOUNDS