  In this study, X-ray absorption spectroscopy (XAS) experiments for
Ni45Co5Mn36.7In13.3 metamagnetic shape memory alloy were performed under high
magnetic fields up to 12 T using a pulsed magnet. Field-induced reverse
transformation to austenite phase caused considerable changes in the magnetic
circular dichroism (MCD) signals and the magnetic moments of the ferromagnetic
coupling between Mn, Ni, and Co were determined. The spin magnetic moment,
Mspin, and orbital magnetic moment, Morb, of Mn atom in the induced austenite
ferromagnetic phase, estimated based on the magneto-optical sum rule, were 3.2
and 0.13 {\mu}B, respectively, resulting in an Morb / Mspin ratio of 0.04. In
the element-specific magnetization curves recorded at 150 K, metamagnetic
behavior associated with the field-induced reverse transformation is clearly
observed and reverse transformation finishing magnetic field and martensitic
transformation starting magnetic field are detected. There was almost no
difference in the magnetically averaged XAS spectrum for Mn-L2,3 edges between
in the martensite and in the magnetic field-induced austenite phases, however,
it was visible for Ni, indicating that Ni 3d-electrons mainly contribute to
martensitic transformation.
