Signature of Austenitic to Martensitic Phase Transition in Ni2MnGa in Mn and Ni K-Edge XANES Spectra
The XANES studies at Mn, Ni and Ga K-edge of Ni2MnGa compound have been carried out at room and low temperatures. The Mn K-edge and Ni K-edge spectra shows modulation in the post edge features when the sample is cooled below martensitic transition temperature. It is strongly reflected in the XANES of Mn K-edge where the peak after the edge gets totally suppressed when the sample is in martensitic phase. This peak shows a hysteretic behaviour when thermal cycling was done across the martensitic transition temperature. This clearly shows that the peak height is a measure of austenitic phase present at a particular temperature. This demonstrates the strong correlations of electronic states and crystal structures in these compounds.
Lluis Mañosa, P.K. Mukhopadhyay and S.R. Barman
V.G. Sathe et al., "Signature of Austenitic to Martensitic Phase Transition in Ni2MnGa in Mn and Ni K-Edge XANES Spectra", Advanced Materials Research, Vol. 52, pp. 175-180, 2008