Exchange anisotropy properties in sulfided iron films

Abstract

Exchange anisotropy, manifested by a shifted B-H loop and a sinθ torque, has been observed in sulfided Fe films. At room temperature, loop shifts along the H axis up to 7 Oe were measured. The B-H loop was shifted in the direction of the field applied during sulfiding and symmetrical about zero H for a field applied perpendicular to this direction. A sinθ torque was present at room temperature in fields up to 20 kOe. At high fields the sinθ torque decreased and the rotational hysteresis increased. The amplitude of the sinθ torque and the B-H loop shift corresponded to an unidirectional anisotropy energy of 0.1 erg/cm2 of apparent interface. Sulfiding of ∼100 Å of a 1000-Å Fe film was sufficient to produce a 7-Oe shift of the B-H loop. © 1966 The American Institute of Physics.