Thin (001) textured FePt and CoPt polycrystalline films (5 nm) were deposited with an MgO polycrystalline underlayer on an oxidized Si substrate followed by a Rapid Thermal Annealing (RTA) process. Structural analysis indicated the samples to be fully ordered after 10 minutes (min) of RTA at 700°C. The magnetic hysteresis exhibited strong perpendicular anisotropy and a coercivity (Hc) between 6 and 8 kOe. The measured and simulated angular dependence of Hc and remanent coercivity (Hre) showed the possibility of domain wall motion or incoherent rotation. δM curves demonstrated strong intergranular exchange coupling. MFM observations showed domain sizes to be 100-200 nm. Activation volumes (Vact) were found to be ~0.4-0.5×10-18 cm 3. The temperature dependence of the coercivity (Hc) indicated a weak pinning mechanism
Published in:
Magnetics, IEEE Transactions on
(Volume:37
,
Issue:
4
)
Date of Publication: Jul 2001