Role of Ni-Mn hybridization in the magnetism of the martensitic state of Ni-Mn-In shape memory alloys

¹ Department of Physics, Goa University - Taleigao Plateau, Goa 403 206, India
² Institute for Solid State Physics, The University of Tokyo - Kashiwa, Chiba 277-8581, Japan
³ Institute of Scientific and Industrial Research, Osaka University - 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
⁴ Tata Institute of Fundamental Research - Homi Bhabha Road, Colaba, Mumbai 400 005, India

^a krp@unigoa.ac.in

Received: 10 January 2011
Accepted: 28 March 2011

Abstract

Extended X-ray Absorption Fine Structure (EXAFS) studies on Ni₅₀Mn_25+xIn_25−x have been carried out at the Ni and Mn K-edge as a function of temperature. Thermal evolution of nearest-neighbor Ni-Mn and Mn-Mn bond distances in the martensitic phase gives a clear evidence of a close relation between structural and magnetic degrees of freedom in these alloys. In particular, the study highlights the role of Ni 3d-Mn 3d hybridization in the magnetism of the martensitic phase of these alloys.