Magnetization reversal in a (110)-oriented epitaxial Er Fe 2 ∕ Dy Fe 2 Laves-phase superlattice

The magnetization reversal of a Laves-phase superlattice has been measured by using unpolarized neutron diffraction and polarized neutron reflectometry. The superlattice ${(6\phantom{\rule{0.3em}{0ex}}\mathrm{nm}\phantom{\rule{0.3em}{0ex}}\mathrm{Er}{\mathrm{Fe}}_{2}∕6\phantom{\rule{0.3em}{0ex}}\mathrm{nm}\phantom{\rule{0.3em}{0ex}}\mathrm{Dy}{\mathrm{Fe}}_{2})}_{40}$ consisted of two hard magnetic materials and was grown by molecular beam epitaxy with the [110] axis along the growth direction. The sample was mounted in a cryomagnet with a vertical field which was aligned along the $[1\overline{1}0]$ direction. The results of the diffraction experiment showed that during the magnetization reversal, the net magnetization reverses through the [221] direction close to the growth axis. The polarized neutron reflectivity confirmed this result and enabled the net layer magnetizations to be measured throughout the reversal. The results showed that both magnetizations were similar, but that the magnetization of the $\mathrm{Dy}{\mathrm{Fe}}_{2}$ reversed over a smaller range of applied fields.