In order to investigate the Fe substituted effects on the magnetic properties of the Ni-Mn-Sn metamagnetic shape memory alloys, magnetization and the Mössbauer spectroscopy measurements were carried out with using
57Fe-doped specimens of Ni
2Mn
1.48−x57Fe
xSn
0.52 (
x = 0.02, 0.04 and 0.08). Singlet-type Mössbauer spectra were clearly observed for
x = 0.02 and 0.04 just below the martensitic transformation temperature,
TM, and above the Curie temperature,
TC, in the austenite phase. It was clear that the magnetic state in the martensite phase just below
TM was paramagnetic for
x = 0.02 and 0.04. In further doped
57Fe to Ni
2Mn
1.48Sn
0.52,
TC in the austenite phase slightly increased. However, the value of
TM significantly decreased. As a result, martensite phase with small spontaneous magnetization directly transformed to the ferromagnetic austenite phase during heating for
x = 0.08. These results obtained from the Mössbauer spectra were consistent with the results of the magnetic measurements in this study and the phase diagram reported by Fukushima
et al. for normal Fe-doped Ni
2Mn
1.48−xFe
xSn
0.52 alloys. The breakdown of the general rule, in which the ferromagnetic shape memory alloys with larger value of the valence electrons per atom,
e/
a, showed higher
TM, was also appeared in Ni
2Mn
1.48−xFe
xSn
0.52 alloys, being similar to Ni
2Mn
1−xFe
xGa alloys.
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