This paper presents a comparative study on the tetragonal magnetostriction constant,λ γ,2 , [ = (3/2)λ 100 ] and magnetoelastic coupling, b 1 , of binary Fe 100-xZ x (0 < x < 35, Z = Al, Ga, Ge, and Si) and ternary Fe-Ga-Al and Fe-Ga-Ge alloys. The quantities are corrected for magnetostrains due to sample geometry (the magnetostrictive form effect). Recently published elastic constant data along with magnetization measurements at both room temperature and 77 K make these corrections possible. The form effect correction lowers the magnetostriction by ∼10 ppm for high-modulus alloys and by as much as 30 ppm for low-modulus alloys. The elastic constants are also used to determine the values of the magnetoelastic coupling constant, b 1 . With the new magnetostriction data on the Fe-Al-Ga alloy, it is possible to show how the double peak magnetostriction feature of the binary Fe-Ga alloy flows into the single peak binary Fe-Al alloy. The corrected magnetostriction and magnetoelastic coupling data for the various alloys are also compared using the electron-per-atom ratio, e/a, as the common variable. The Hume-Rothery rules link thee/a ratio to the regions of phase stability, which appear to be intimately related to the magnetostriction versus the solute concentration curve in these alloys. Using e/a as the abscissa tends to align the peaks in the magnetostriction and magnetoelastic coupling for the Fe-Ga, Fe-Ge, Fe-Al, Fe-Ga-Al, and Fe-Ga-Ge alloys, but not for the Fe-Si alloys for which the larger atomic size difference may play a greater role in phase stabilization. Corrections for the form effect are also presented for the rhombohedral magnetostriction,λ ɛ,2 , and the magnetoelastic coupling, b 2 , of Fe 100-x Ga x (0 < x < 35) alloys.Keywords aluminium alloys, elastic constants, elastic moduli, gallium alloys, germanium alloys, iron alloys, magnetisation, magnetoelastic effects, magnetostriction, silicon alloys
Disciplines
Condensed Matter Physics | Metallurgy
CommentsThe following article is from Journal of Applied Physics 111 (2012) This paper presents a comparative study on the tetragonal magnetostriction constant, k c,2 , [ ¼ (3/2) k 100 ] and magnetoelastic coupling, b 1 , of binary Fe 100-x Z x (0 < x < 35, Z ¼ Al, Ga, Ge, and Si) and ternary Fe-Ga-Al and Fe-Ga-Ge alloys. The quantities are corrected for magnetostrains due to sample geometry (the magnetostrictive form effect). Recently published elastic constant data along with magnetization measurements at both room temperature and 77 K make these corrections possible. The form effect correction lowers the magnetostriction by $10 ppm for high-modulus alloys and by as much as 30 ppm for low-modulus alloys. The elastic constants are also used to determine the values of the magnetoelastic coupling constant, b 1 . With the new magnetostriction data on the Fe-Al-Ga alloy, it is possible to show how the double peak magnetostriction feature of the binary Fe-Ga alloy flows into the single peak binary Fe-Al alloy. The corrected magnetostriction and magnetoel...