Luminescence-based magnetic imaging with scanning x-ray transmission microscopy

We demonstrate the imaging of the magnetic domain configuration of cobalt structures fabricated on MgO(001) using x-ray induced optical luminescence in a scanning transmission microscope. The technique relies on the measurement of the magnetization-dependent x-ray absorption probed by the optical luminescence radiated from the MgO substrate and induced by the x-rays transmitted through the magnetic layer. This method enables the measurement of the electronic and magnetic spectroscopic properties of single crystalline layers and buried heterostructures with nanometer lateral resolution and elemental sensitivity and opens scanning transmission x-ray microscopy to materials which cannot be grown on membranes or as freestanding thin films.