Magnetic characterization of intermetallic compound FePt and FePtX (X = B,Ni) thin films

VSM rotational transverse magnetization technique was used to characterize the anisotropy field of FePt and FePtX (X = B, Ni) thin films with comparis on to commercial CoCrTaPt media. Anisotropy energy was derived. H-c/H-k was used as an indicator for coherent rotation of a single domain. Interaction s between magnetic domains were characterized by Kelly-Henkel plot. Interac tive field factor was used as a coupling factor similar to delta M. Correla tions between coercive force, magnetic anisotropy of grains, and the degree of magnetic isolation among grains were discussed. B and Ni had been added as diluting agent to the FePt system to decrease saturation magnetization, coercivity, anisotropy field and anisotropy energy. These doping elements also decrease the magnetic coupling between neighboring domains, and promot e coherent rotation inside each domain. (C) 1999 Elsevier Science B.V. All rights reserved.