Nanoscale imaging of buried topological defects with quantitative X-ray magnetic microscopy

Abstract

Angular dependence of magnetic transmission X-ray microscopy has been used as the basis of a novel imaging technique that provides quantitative descriptions of magnetic configurations with nanometric lateral resolution (canting angles relative to surface normal and sense). This method is applied to study magnetic stripe domains of ferromagnetic NdCo5 layers in which canting angles are found to decrease from 65° to 22° as Nd-Co thickness increases from 55 to 120 nm. Element specific X-ray images of a NdCo/Permalloy bilayer have allowed us to characterize independently the magnetization at each layer. Complex topological defects (merons or ½ skyrmions) have been identified within the stripe pattern of the NdCo film that are only partially replicated by the permalloy overlayer. These results open possibilities for the characterization of deeply buried magnetic topological defects, nanostructures and devices.