The thermal expansion, spontaneous volume magnetostriction ωs, forced volume magnetostriction ( ∂ω ∂H) and Young's modulus of amorphous Fe-B, Fe-P, Co-B and (Fe-M)77Si10B13 (M = Cr, Mn, Co, Ni) alloys have been measured to make clear the magnetovolume effect in transition metal-metalloid amorphous alloys. The thermal expansion coefficient α, ωs and ( ∂ω ∂H) are dependent on the number of d-electrons per transition metal atom neff calculated based on the charge transfer model. The neff vs. α, ωs and ( ∂ω ∂H) curves are quite similar to the corresponding curves in fcc alloys. The maxima in those curves are, however, found at neff ≈ 8.2 for the amorphous alloys in contrast with neff ≈ 8.7 for the fcc Fe-Ni alloys. On the other hand, Young's modulus measured under the saturation of magnetization is governed by the molar volume, irrespective of neff. The magnetovolume effect in transition metal-metalloid amorphous alloys is discussed in connection with the instability of ferromagnetism of amorphous Fe.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics