Proximity effects in Fe1-xCox/Mn/Fe1-xCox trilayers

We report on the first results of a structural and magnetic investigation of Fe1-xCox/Mn/Fe1-xCox trilayers (x = 0-0.75). In situ low energy electron diffraction shows that Mn grows epitaxially on bcc Fe1-xCox (x less than or equal to 0.75) with a good crystallinity up to 30 Angstrom. Reflectivity and small angle diffuse scattering of synchrotron radiation reveal sharp interfaces, each of them having two lateral characteristic lengths in the height-height correlation function that differ bg one order of magnitude. The long-range height-height correlation function is vertically correlated and the short-range one is not. From magneto-optical Kerr effect measurements, evidence for non-collinear coupling between Fe1-xCox layers (x = 0 and 0.5) was found for Mn spacer thicknesses below 12 Angstrom. Polarized neutron reflectometry performed at 300 K reveal a net magnetization of 0.8 +/- 0.3 mu (B)/at in the Mn layer in Fe0.5Co0.5/Mn/Fe0.5Co0.5 and no net magnetization in the Mn layer in Fe/Mn/Fe. (C) 2001 Elsevier Science B.V. All rights reserved.