MAGNETIZATION DENSITY PROFILES IN MAGNETIC MULTILAYERS. J A C Bland, Cavendish Laboratory, Madingley Road, Cambridge, CB3 OHE, UK

The capabilities of polarized neutron reflection (PNR) for directly determining the magnetic and non-magnetic structure in thin and ultrathin magnetic films and multilayers are reviewed. It is shown that the vector magnetization density profile can be obtained with atomic layer resolution in favourable cases and that the combination of structural and magnetic information provides decisive advantages. Estimates of the interface roughness and layer thicknesses can be accurately made and diffuse scattering measurements can be used to probe spin disorder at interfaces. The magnetisation profile across chemically homogeneous ultrathin films can be accurately measured and examples of recent measurements in both ultrathin Fe films and trilayer structures are given and compared with the results of conventional magnetometry measurements. Vector magnetometry measurements of the layer dependent magnetic moment orientations are shown to provide a powerful approach to the study of coupling behaviour in ferromagnetic (FM)/non-magnetic (NM)/FM trilayer structures. Finally the thickness dependent magnetic moment of epitaxial Cu/fcc Ni/Cu(001) structures with competing perpendicular and shape anisotropies is determined as a function of applied field and compared with the results of magnetometry measurements. A strong variation in moment is found which is reflected in the variation of the ratio of orbital and spin moments with thickness determined from X-ray circular dichroism (XMCD) experiments.