Towards a 3D magnetometry by neutron reflectometry

Specular polarised neutron reflectometry with polarisation analysis allows one to probe in-depth magnetic profiles of thin films (along the normal to the film). Off-specular reflectometry gives information about lateral structures (in the plane of the film) with typical lengthscales ranging from 5 to 100 mu m. Furthermore, surface diffraction at grazing angle gives access to transverse dimensions between 10 nm and 300 nm with a resolution in that direction of a few nanometers. The combination of these three techniques applied to magnetic systems can lead to a 3D magnetic structure-measurement, Such a technique is however not applicable to the study of a single magnetic dot, but it can generate unique results in several cases including patterns of domain walls in thin films with perpendicular anisotropy, arrays of magnetic dots, and patterned lines in magnetic thin films. (C) 1999 Published by Elsevier Science B.V. All rights reserved.