Imaging the Cone State of the Spin Reorientation Transition

The magnetization behavior and the domain pattern in remanence are studied in $\mathrm{Co}/\mathrm{Pt}$ multilayers. The reorientation of magnetization from perpendicular to in plane is found to happen via the state of canted magnetization. In the transition from an easy axis to an easy plane a stable domain pattern in the in-plane magnetization components is found for $\mathrm{Co}/\mathrm{Pt}$ multilayers. The analysis of the domain pattern reveals that the magnetization canting is such that all in-plane orientations of magnetization are equally occupied. The found structure is appointed to the cone state.

Figure 1

(a) Polar Kerr-rotation (perpendicular field) irreversible behavior for high magnetic fields and reversible behavior for low fields and (b) longitudinal Kerr ellipticity (in-plane field) loop with switching around 5 mT (inset) and reversible behavior for high fields.

Figure 2

In plane magnetic microstructure of a $\mathrm{Co}/\mathrm{Pt}$ multilayer film in remanence after saturation in a perpendicular field. The SEMPA image shows the distributions of the (a) vertical and (b) horizontal polarization component. (c) Histogram of the spin polarization. (d) Color plot of the in-plane magnetization pattern.

Figure 3

Magnetic microstructure of a $\mathrm{Co}/\mathrm{Pt}$ multilayer. The film was tilted with respect to the detector plane. The SEMPA image shows the distributions of the (a) vertical and (b) horizontal polarization component. (c) Histogram of the spin polarization.

Figure 4

Schematic drawing of the projection of a canted magnetization state on the detector plane.