Superlattices and Microstructures vol:34 issue:1-2 pages:87-105
We report on the use of specular and off-specular polarized neutron reflectometry (PNR) for the study of magnetization reversal in patterned magnetic structures. We discuss the instrumental requirements and the measurement method and illustrate its potential by applying it to lithographically structured trilayer systems of the form (7.5 nm Au/20 nm Co/7.5 rum Au) prepared on oxidized Si wafers. In order to study the influence of the shape of the structures on the magnetic properties we prepared rectangular bars with a width of 1 mum and a length of 4 mum. The dots were arranged in a square lattice symmetry with a period of 10 mum. By using a two-dimensional position sensitive detector (PSD) we were able to record not only the specularly but also the off-specularly scattered intensity which has maxima at particular angles due to the in-plane periodicity of the discs. The second system that we studied is that of wires with a width of 2 mum and a period of 15 mum consisting of an exchange biased Co/CoO bilayer structure. By applying neutron spin analysis and monitoring the neutron reflectivity at a fixed angle of incidence as a function of an external magnetic field we were able to effectively study the magnetization reversal process in both systems. (C) 2004 Elsevier Ltd. All rights reserved.