AVS 46th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Friday Sessions
       Session MI-FrM

Paper MI-FrM9
Enhancement of Perpendicular Magnetic Anisotropy and Surface Alloy of Co/Pt(111) Ultrathin Films

Friday, October 29, 1999, 11:00 am, Room 618/619

Session: Magnetic Thin Films
Presenter: Y.E. Wu, National Taiwan Normal University, ROC
Authors: C.S. Shern, National Taiwan Normal University, ROC
H.Y. Her, National Taiwan Normal University, ROC
Y.E. Wu, National Taiwan Normal University, ROC
Correspondent: Click to Email
The magnetic anisotropy of Co/Pt(111) was studied by surface magneto-optic Kerr effect (SMOKE). The perpendicular magnetic anisotropy appears for Co deposited on a flat Pt(111) surface with a thickness between 0.8 and 3.7 ML. The perpendicular uniaxial magnetic anisotropy disappears for Co deposited on a sputtered Pt(111) surface because the magnetocrystalline anisotropy has diminished due to the absence of crystalline structure in the films. During surface alloy formation in 1 ML Co on the flat Pt(111) surface, we quantitatively demonstrate an enhancement in the magneto-optic Kerr signal. The maximum enhancement in MO signal is as large as 200 % after alloy formation at 710 K. The formation of Co-Pt alloy was confirmed by AES and LEED. The perpendicular magnetic anisotropy persists in the annealing process until the ultrathin film is annealed at temperatures above 850 K. The enhancement is also observed in thicker films when the formation of Co-Pt alloy has been developed, but both the out-of-plane and the in-plane anisotropy appear at a higher annealing temperature.