Growth and characterization of L10 FePt and CoPt ⟨001⟩ textured polycrystalline thin films

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 degreesC. The magnetic hysteresis exhibited strong perpendicular anisotropy and a coercivity (H-c) between 6 and 8 kOe. The measured and simulated angular dependence of He and remanent coercivity (H-rc) showed the possibility of domain wall motion or incoherent rotation. deltaM curves demonstrated strong intergranular exchange coupling. MFM observations showed domain sizes to be 100-200 nm. Activation volumes (V-act) were found to be similar to0.4-0.5 x 10(-18)cm(3). The temperature dependence of the coercivity (H-c) indicated a weak pinning mechanism.