Highly (001)-oriented Ni-doped L1 FePt films and their magnetic properties

We report on Ni-doped nonepitaxial L10 FePt thin films with strong (001) texture. The influences of Ni doping on L10 ordering, orientation, and the magnetic properties of the FePt films have been investigated. In-plane and out-of-plane x-ray diffractions (XRD) were used to analyze the texture of FeNiPt films. For [Fe(0.38nm)∕Ni(0.04nm)∕Pt(0.4)]13 sample, the out-of-plane XRD data showed only (00l) peaks and in-plane data showed (hk0) peaks after annealing, indicating high (001) texture of the FeNiPt films. In comparison with FePt, the (00l) peak positions shifted to higher angle, indicating partial Ni substitution in the L10 lattice. The coercivity, measured at room temperature, decreased as a function of Ni doping. For the film with a Ni layer thickness of 0.06nm, the coercivity is about 6kOe after annealing, which is suitable for the writing performance of high-anisotropy perpendicular recording media.