Mossbauer studies on structural ordering and magnetic properties of melt-spun Ni-Fe-Ga ribbons

Ribbons of ferromagnetic shape memory Ni(2+x)Fe(1-x)Ga (x=0 and 0.12) alloys were prepared at wheel speeds of 12 and 35 m/s by melt spinning technique. The structural (site) disorder and the associated changes in the magnetic properties of the ribbons were investigated by (57)Fe Mossbauer spectroscopy and magnetization measurements respectively. Mossbauer spectra of Ni(2)FeGa ribbon revealed the presence of both L2(1) order and B2-like disorder with some amount of Fe antisite atoms on Ni site. The increase in Ni content was found to decrease the T(C) while its effect on T(M) was the opposite way.