Microstructure and magnetic properties of highly textured Sm(Fe0.8Co0.2)12 thin films with ThMn12 structure

Abstract

The out-of-plane XRD pattern of the Sm(Fe0.8Co0.2)12 thin film shows strong (002) and (004)diffraction peaks. By tiling the sample, we clearly observe the superlattice peaks of (132) and(332), which indicates that this film has ThMn12 structure. The cross-sectional TEM image ofa Sm(Fe0.8Co0.2)12 thin film shows the columnar-shaped Sm(Fe0.8Co0.2)12 grains on theNiTa/MgO/V underlayer using SiO2 substrate. Magnetization curves for the films before andafter the diffusion process show perpendicular magnetic anisotropy, which corresponds to thec-axis orientation observed from the XRD pattern. A polycrystalline Sm(Fe0.8Co0.2)12perpendicular anisotropy film shows the coercivity of 0.5 T before Cu diffusion, giving rise tothe (BH)max value of 386 kJ/m3, if demagnetization correction with demagnetization factor N⊥ =0.45 is assumed. Moreover, the coercivity can be further enhanced to 0.8 T by thediffusion of Cu.