High perpendicular anisotropy and magneto-optical activities in ordered Co3Pt alloy films

The origin of the large perpendicular magnetic anisotropy constant K-u of Co3Pt alloy thin films is discussed. The films deposited onto Al2O3(0001), Al2O3(11 (2) over bar 0), and MgO(111) substrates held at 230-350 degrees C during deposition exhibit K-u of the order of 10(7) erg/cm(3) at room temperature. While the one dimensional long range order parameter S estimated by x-ray diffraction is very consistent with the development of the perpendicular magnetic anisotropy in the films deposited at 380-450 degrees C, very little evidence is found to suggest the correlation between S and K-u for the lower deposition temperature range (230-380 degrees C). To explain this, a short range ordering is suggested to be responsible for the origin of K-u, similar to the cases in Pt72Co28 alloys. The magneto-optical polar Kerr activity of ordered Co3Pt film is found to be enhanced for both theta(K) and eta(K) in the photon energy range from 2 to 4 eV. (C) 1998 American Institute of Physics. [S0021-8979(98)43611-9].