Magnetic properties of nanostructured CoPt and FePt thin films

Polycrystalline MgO underlayer films lead to different preferred orientations of L1/sub 0/ CoPt and FePt films after the annealing process, depending on the thickness of the L1/sub 0/ films. L1/sub 0/ films with a thickness greater than 20 nm revealed mostly L1/sub 0/ [100] fiber texture and consequently in-plane anisotropy as determined by magnetic hysteresis. Strong perpendicular anisotropy due to the L1/sub 0/ [001] fiber texture was obtained for thicknesses below 10 nm. The /spl delta/M curve showed strong intergranular exchange coupling. The angular variation of coercivity showed the possibility of both domain wall motion and a rotational mechanism of magnetization reversal.