Probing magnetic structures by neutron reflectometry: Off-specular scattering from interfaces and domains in FeCoV/TiZr multilayers

Polarized neutron reflectometry (PNR) is commonly used to characterize the depth-dependent nuclear density and magnetization profiles of thin films an d multilayers. While specular reflectivity is connected with characteristic s perpendicular to the sample surface, in-plane features cause off-specular scattering. In this work we present time-of-flight PNR results on (FeCoV/T iZr) multilayers with applied fields parallel to the in-plane easy axis of magnetization. Our measurements at low applied fields clearly show diffuse scattering. We attribute this scattering to randomly oriented magnetic doma ins, with no coupling between the magnetic FeCoV layers, With increasing ap plied field the domain scattering decreases. At the same time, off-specular scattering with a well-defined relation between the wavelength and the sca ttering angle increases with increasing applied field. This type of scatter ing can be attributed to correlated interfaces. (C) 2001 Elsevier Science B ,V, All rights reserved.