Lattice strain accommodation and absence of pre-transition phases in Ni50Mn25+ xIn25- x

R Nevgi; K R Priolkar; L Righi; M Solzi; F Cugini; E T Dias; A K Nigam

doi:10.1088/1361-648X/abb17f

Lattice strain accommodation and absence of pre-transition phases in Ni₅₀Mn_{25+ x}In_{25- x}

J Phys Condens Matter. 2020 Sep 23;32(50). doi: 10.1088/1361-648X/abb17f.

Authors

R Nevgi¹, K R Priolkar¹, L Righi², M Solzi³, F Cugini³, E T Dias⁴, A K Nigam⁴

Affiliations

¹ Department of Physics, Goa University, Taleigao Plateau, Goa 403206, India.
² Department of Chemistry, Parma University, Parco Area delle Scienze 17/a 43124 Parma, Italy.
³ Department of Mathematical, Physical and Computer Sciences, University of Parma, Parco Area delle Scienze 7/A 43124 Parma, Italy.
⁴ Department of Condensed Matter Physics and Material Science, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India.

PMID: 32985415
DOI: 10.1088/1361-648X/abb17f

Abstract

The stoichiometric Ni₅₀Mn₂₅In₂₅Heusler alloy transforms from a stable ferromagnetic austenitic ground state to an incommensurate modulated martensitic ground state with a progressive replacement of In with Mn without any pre-transition phases. The absence of pre-transition phases like strain glass in Ni₅₀Mn_25+xIn_25-xalloys is explained to be the ability of the ferromagnetic cubic structure to accommodate the lattice strain caused by atomic size differences of In and Mn atoms. Beyond the critical value ofx= 8.75, the alloys undergo martensitic transformation despite the formation of ferromagnetic and antiferromagnetic clusters and the appearance of a super spin glass state.

Keywords: XAFS; magnetic properties; magnetic shape memory alloys.