Depth-resolved photoemission spectroscopy with soft X-ray standing waves

Depth-resolved soft X-ray photoemission spectroscopy (SXPS) is performed in which depth sensitivity is provided by use of a periodic multilayer [B4C ( 22.5 Angstrom)/W (17.1 Angstrom)(40)] that shows sizeable standing wave eff ects of +/- similar to 50-60% for soft X-rays at hv approximate to 750 eV. The photoelectron intensities of each element in the sample, including impu rity overlayers, are sharply altered when the incidence angle is tuned over the Bragg condition, in excellent agreement with theoretical simulations. The angular dependence of the photoelectron intensity also shows unique che mical-state resolved behavior depending on the location of a given species in the multilayer structure. Depth-resolved SXPS with soft X-ray standing w ave excitation should thus be a very useful tool for studying surface and i nterface chemical, electronic and magnetic properties. (C) 2001 Elsevier Sc ience B.V. All rights reserved.