Magnetic torque behavior and rotational hysteresis of amorphous uniaxial Sm-Co alloy films

Abstract

Amorphous films of Sm_100−x Co _x with 70≦x≦90 were made by vapor deposition on flat glass substrates at 300 K with a magnetic field parallel to the film plane, as described in a preceding paper; the field induces a uniaxial anisotropyK _u of the order 10⁶ erg cm⁻³ with the easy axis,x, in the film plane. The film plane (xy plane) is the easy plane with a planar anisotropyK _p of the order 10⁷ erg cm⁻³, i.e. the film normal,z, is the hard axis. For such films, torque curvesT(H, Θ) (Θ: angle betweenH and an axis normal to the axis of rotation) are calculated, and are measured in fieldsH ≦ 30 kOe for the three axes of rotation,x, y, andz. The results are evaluated to give the “spontaneous magnetization”, 〈M〉, the anisotropies,K _u ,K _p , the rotational hysteresis losses,W _Rx (H),W _Ry (H),W _Rz (H), and the rotational hysteresis integrals,R _x ,R _y ,R _z .