Magnetic and magneto-optical properties and structure for (Co100-xFex)50Pt50 alloy thin films

The intrinsic perpendicular magnetic anisotropy constant K-u of (Co100-xFex)(50)Pt-50 (0 less than or equal to x less than or equal to 100) alloy thin fllms is determined at room temperature. It is found to increase with order parameter S, and decrease with the tetragonality c/a for all compositions. The estimated K-u values obtained by the extrapolation to S = 1 are nearly identical for x from 0 to 56, but increase for x beyond 56. The polar Kerr rotation is found to become more enhanced for photon energies near 1.4 similar to 3.5 eV and 4 similar to 6.8 eV with increasing x. Observations of domain structures in Fe50Pt50 thin films reveal an induced in-plane magnetic anisotropy when the thickness exceeds 1000 Angstrom.