Perpendicular anisotropy and oscillatory interlayer coupling in Fe0.5Co0.5/Rh/Fe0.5Co0.5 bilayers on Rh(001)

Tetragonal distortion in Fe-0.Co-5(0.5) alloy films grown epitaxially on Rh (001) substrates results in an easy magnetization axis perpendicular to the film plane up to the thickness of 17 ML. The distortion is supported by a Rh-overlayer; thus the strong perpendicular anisotropy can be kept when another Fe0.5Co0.5 film is grown on top of the Rh/Fe0.5Co0.5/Rh(001) structure. Depending on the thickness of the Rh spacer, the top and bottom Fe0.5Co0.5 films are either ferro- or antiferromagnetically coupled. The net magnetization of the antiferromagnetically coupled Fe0.5Co0.5/Rh/Fe0.5Co0.5 bilayer switches at the field which depends on the difference between magnetizations of both the Fe0.5Co0.5 layers. The final covering of the Fe0.5Co0.5/Rh/Fe0.5Co0.5/Rh(001) structure with Rh increases the switching field. The effect is explained by a locally enhanced magnetization in the Rh/Fe1-xCox interfaces. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3065984]