Abstract
An in-plane perpendicular magnetic coupling between and Co has been found in trilayers for a NiO thickness ranging from 4 to 25 nm by magneto-optical Kerr effect and x-ray magnetic circular dichroism measurements. In the easy magnetization direction of the Co layer, the Co coercive field increases when the thickness of the NiO layer increases. Because of the coupling, is always larger than for bilayers with the same thicknesses. The saturation field of the NiFe layer decreases when increases, indicating a weakening of the coupling. Numerical simulations show that the presence of interface roughness combined with a small value of the NiO anisotropy can explain the observed coupling.
- Received 19 June 2002
DOI:https://doi.org/10.1103/PhysRevLett.91.027201
©2003 American Physical Society