SXSPM Research | Highlights
Improving the detection of spin-dependent x-ray excitations via sample bias
The ability to position a sharp probe in close proximity to a sample while monochromatic x-rays illuminate the surface opens a path to localized spectroscopy and imaging with chemical and magnetic contrast. We have employed a scanning tunneling microscope for the local study of the x-ray magnetic circular dichroism (XMCD) signal of a patterned ferromagnetic ring structure. An insulator-coated tip was positioned about 200 nm over the sample surface. The tip current exhibits a strong dependence on the bias between the tip and the sample. A negative sample bias is required in order to enhance the dichroism signal at the tip.