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

Temperature-dependent spin momentum densities in Ni2Mn1.4Sn0.6 shape memory alloy have been measured using 182 keV circularly polarized synchrotron radiations. Near the martensitic phase transition $(T_{\mathrm{M}}=200\ \text{K})$ , 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