HIGH-RESOLUTION POSITRON-ANNIHILATION-INDUCED AUGER-ELECTRON SPECTROMETER

Positron-annihilation-induced Auger electron spectroscopy (PAES) uses a beam of low-energy positrons to excite Auger transitions via annihil ation of core electrons. This mechanism imbues PAES with a high degree of surface specificity and the ability to eliminate the large collisi onally induced secondary-electron background typically present in conv entional Auger spectra. Here, we describe a high-resolution PAES syste m with an energy resolution Delta E/E = 2.5%, approximately five times better than previous PAES spectrometers. The system consists of a com pact low-energy (similar to 10 eV) electrostatically focused positron beam sind a large cylindrical mirror analyzer. High-resolution PAES sp ectra from Cu(100) and Ge(100) surfaces are presented to illustrate th e capabilities of the system. Energy spectra of secondary electrons an d reemitted positrons resulting from bombardment of the surface by low -energy positron are also presented. (C) 1997 American Institute of Ph ysics.