We have developed a three-axis configurational in situ SMOKE apparatus by which three-dimensional vector
magnetization reversal processes are studied for ultrathin Co films grown on a Pd (111) single 얀ystal in the
thickness range of spin reorientation transition. This study pro찌des a better understanding of magnetization
reversal motions with the knowledge of three components of the magnetization vector at the transition of an
easy axis of magnetization from the film normal at 5 ML Co to in-plane at 6 ML Co (ML denotes monolayer).
For a 5.25 ML Co, it was observed that a slightly canted magnetization vector from the film normal rotated in
the film plane under an applied field direction paraUel to the film normal.