A Mössbauer spectroscopy and neutron diffraction study of magnetostrictive, melt-spun Fe–Ga alloy ribbons

• Published in: Journal of magnetism and magnetic materials Vol. 324; no. 22; pp. 3817 - 3823
• Main Authors: Mellors, N.J., Zhao, X., Simmons, L.M., Quinn, C.J., Kilcoyne, S.H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2012; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Ferromagnetism; Magnetic properties and materials; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Magnetomechanical and magnetoelectric effects, magnetostriction; Magnetostrictive alloy; Melt spun FeGa alloy; Mössbauer effect; other γ-ray spectroscopy; Mössbauer spectroscopy; Neutron diffraction; Physics; Short-range order; Short-range order; Ferromagnetism; Melt spun FeGa alloy; Neutron diffraction; Magnetostrictive alloy; Mössbauer spectroscopy; Hyperfine magnetic field; Moessbauer effect; Annealing; Magnetostriction; Phase transformations; Melt spinning; Iron alloys; Gallium alloys; BCC lattices; Rapid solidification; Chemical composition
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2012.06.021

Ribbons of Fe100−xGax (x=15, 17.5, 19.5 and 22.5) were prepared by rapid solidification from the melt. 57Fe Mössbauer spectroscopy and high resolution neutron diffraction have revealed that Fe100−xGax alloys with x=15 and 17.5 have the disordered bcc (A2) structure even after annealing, but the alloy with x=19.5 developed the short-range ordered D03 phase when annealed. The x=22.5 alloys showed mainly D03 phase with a fraction of bcc phase. A fraction of the bcc phase transformed into D03 phase and the long-range ordering of D03 phase was improved after annealing. 57Fe Mössbauer spectra showed no observable L12 phase in any samples even though less than 1% volume of L12 phases has been found in the annealed samples by neutron diffraction. The additional absorption at hyperfine field of 25T in x=22.5 samples was regarded as a result of imperfect D03 structure, rather than L12 phase. ► Melt-spun Fe100−xGax alloys with 15≤x≤17.5 have a disordered bcc structure. ► Ribbons with x=19.5 develop short-range ordered D03 phase upon annealing. ► The x=22.5 ribbons show mainly D03 phase with a fraction of bcc phase.