Evidence for in-plane antiferromagnetic domains in ultrathin NiO films

Ultrathin films of NiO grown on Ag(100) were investigated by photoemission microscopy. To image antiferromagnetic domains, linearly polarized light from an insertion device was used. The micrographs revealed lateral changes of the spectral line shapes of the 3p photoemission spectrum which were confirmed by taking full spectra with a lateral resolution of 150 nm (microspectroscopy). These changes indicate the presence of antiferromagnetic domains which can be distinguished because the magnetic moments (or components thereof) are either collinear or perpendicular to the electric field vector of the linearly polarized light.