Spin reorientation in NdCo5
The NdCo5 phase undergoes a temperature driven spin reorientation transition, i.e. a change of the easy direction of magnetization, from easy c-axis via easy cone to easy plane. In order to achieve a deeper understanding of the magnetization processes of thin films during such a transition we prepare epitaxial films with the orientation of the crystallographic c-axis either along a single in-plane direction of the substrate or along the substrate normal. The figure below displays exemplary hysteresis loops at 400 and 200 K. At 400 K it clearly reveals an easy c-axis with the a-axis being magnetically hard, which changes to the opposite behaviour at 200 K. From temperature dependent measurements the transition temperatures toward easy-cone and easy-plane were determined to 310 and 255 K.
At temperatures below 100 K this RE-Co phase possesses an anisotropy also within the basal plane, with a magnetically slightly harder b-axis compared to the a-axis. This effect can best be observed in an epitaxial film with perpendicular c-axis (see: M. Seifert, L. Schultz, and V. Neu, J. Appl. Phys. 107, 09A711 (2010)).
- M. Seifert, L. Schultz, and V. Neu, Magnetization processes and spin reorientation in epitaxial NdCo5±x thin films, J. Appl. Phys. 106, 073915 (2009).
- M. Seifert, L. Schultz, and V. Neu, Investigation of the c-axis and basal plane anisotropy in epitaxial NdCo5 thin films, J. Appl. Phys. 107, 09A711 (2010).