Temperature-dependent spin magnetization density in Mn-rich Ni-Mn-Sn shape memory alloy by magnetic Compton scattering

¹ Department of Physics, M. L. Sukhadia University - Udaipur 313001, India
² Department of Physics, University of Mumbai - Vidyanagri, Santacruz (E), Mumbai 400098, India
³ Department of Physics, Goa University - Goa 403206, India
⁴ Solid State Physics Division, Bhabha Atomic Research Centre - Mumbai 400085, India
⁵ Experimental Research Division, Japan Synchrotron Radiation Research Institute, SPring-8 Mikazuki, Hyogo 679-5198, Japan

^(a) blahuja@yahoo.com

Received: 21 March 2014
Accepted: 21 June 2014

Abstract

Temperature-dependent spin momentum densities in Ni₂Mn_1.4Sn_0.6 shape memory alloy have been measured using 182 keV circularly polarized synchrotron radiations. Near the martensitic phase transition , experimental magnetic Compton profiles (MCPs) unravel a dominating spin moment contribution from Mn sites. First-principles calculations are found to produce higher magnetic moment for orthorhombic structure than that for the L2₁ (cubic) structure, which is in tune with the present MCP data. It is also concluded that the spin moments of excess Mn atoms lying at Sn sites are antiferromagnetically coupled with Mn local spin moment in both the phases.