Magnetic Properties and Nanostructures of FePtCu:C Thin Films with FePt Underlayers

Magnetic properties and nanostructures of FePtCu:C thin films with FePt
underlayers (ULs) are studied. The effect of FePt ULs on the orientation and magnetic properties of the thin films are investigated by adjusting FePt UL thicknesses from 2nm to 14nm. X-ray diffraction (XRD) scans reveal that the orientation of the films is dependent on FePt UL thickness. For a 5-nm FePtCu:C nanocomposite thin film with a 2-nm FePt UL, the coercivity is 6.5KOe, the correlation length is 59nm, the desired face-centred-tetragonal (fct) ordered structure L1₀ phase is formed and the c axis normal to the film
plane (001) texture is obtained. These results indicate that the better orientation and magnetic properties of the films can be tuned by decreasing the thickness of the FePt UL.