Magnetic properties of nanostructured CoPt and FePt thin films

Polycrystalline MgO underlayer films lead to different preferred orientations of L1(0) CoPt and FePt films after the annealing process, depending on the thickness of L1(0) films. L1(0) films with a thickness greater than 20 nm revealed mostly L1(0) [100] fiber texture and consequently in-plane anisotropy as determined by magnetic hysteresis, Strong perpendicular anisotropy due to the L1(0) [001] fiber texture was obtained for thicknesses below 10 nm, The deltaM 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.