In situ vectorial magnetization study of ultrathin magnetic films using a surface magneto-optical Kerr effect measurement system

The three-configuration in situ surface magneto-optical Kerr effect (SMOKE) system, which enables full vectorial analysis of magnetization for ultrathin magnetic films in a UHV chamber, has been developed. The system has been applied to in situ measurements of the three components of magnetization vector of Co films in an applied magnetic field at the thickness range of 5/spl sim/6 ML, where the spin reorientation was found to occur. We observed contrasting vectorial magnetization reversal behavior dependent on the Co thickness: In particular, for 5.25 ML of Co, a slightly canted magnetization vector from the film normal rotates in the film plane under an applied field normal to the film plane.