X-ray resonant magnetic scattering experiments using linear and circular polarized light were performed at the Ni Lz3 absorption edges on a Ag/Ni multilayer.A superlattice magnetic peak, due to the antiferromagnetic coupling between Ni layers, is evidenced. In the case of a ferromagnetic coupling, large changes in the charge peak (up to 15%) are observed upon reversal of the direction of the magnetic field. The magnetic scattering amplitude is evaluated to SI. O per nickel atom. Sum rules have been applied for the first time to the energy-dependent magnetic amplitude.

The design of a high resolution photoemission electron microscope ͑PEEM͒ for the study of magnetic materials is described. PEEM is based on imaging the photoemitted ͑secondary͒ electrons from a sample irradiated by x rays. This microscope is permanently installed at the Advanced Light Source at a bending magnet that delivers linearly polarized, and left and right circularly polarized radiation in the soft x-ray range. The microscope can utilize several contrast mechanisms to study the surface and subsurface properties of materials. A wide range of contrast mechanisms can be utilized with this instrument to form topographical, elemental, chemical, magnetic circular and linear dichroism, and polarization contrast high resolution images. The electron optical properties of the microscope are described, and some first results are presented.