Magnetostriction and Magnetic Anisotropy of Ni and Ni–Pd Alloys

Magnetostriction constants of Ni–Pd alloys containing 0∼90 at% Pd were measured above 77 K with the (001) and (011) disks by means of a strain gauge technique. The higher order magnetostriction constants h 3 ∼ h 5 were found to be negligibly small in comparison with the lower order constants h 1 and h 2 . The values of h 1 and h 2 at 0 K determined by the extrapolation increase in magnitude with an increase of the Pd concentration, and reach the maximum of about -3.4×10 -4 and -1.6×10 -4 for h 1 and h 2 , respectively, around 70 at% Pd. At 0 K, the contribution of the magnetoelastic term ( K 1 ) M.E. to the effective magnetic anisotropy constant K 1 was found to be negligibly small, so that it is possible to regard K 1 as the intrinsic magnetic anisotropy constant ( K 1 ) 0 . The concentration dependence of h 1 and h 2 , and of ( K 1 ) 1 is qualitatively discussed.