Langmuir, Vol.19, No.19, 7789-7793, 2003
Off-specular polarized neutron reflectometry from periodic arrays of lithographically structured Co dots
We studied the off-specular intensity in polarized neutron reflectivity from regular arrays of circular and rectangular Co dots with sizes in the micrometer range. The dots were lithographically prepared and placed on a square lattice with a period of 10 mum, the rectangular dots having an aspect ratio of 4:1. In both cases, we observed enhanced intensity at particular angles off the specular condition. The positions of these satellites are correlated to the lateral periodicity of the ferromagnetic dots. The magnetic information could be revealed by measuring the off-specular intensity as a function of the magnetic field applied in-plane parallel to the rows of the dots. The magnetization reversal process could be analyzed by separating the spin-flip and non-spin-flip contributions to the off-specular signal. The measured spin-flip intensities clearly prove that for both samples the magnetization reversal is dominated by domain wall movement and not by a uniform rotation of single-domain particles.