High resolution positron annihilation induced Auger electron spectroscopy of the CuM2,3VV-transition and of Cu sub-monolayers on Pd and Fe

We present a high resolution positron annihilation induced Auger Electron Spectroscopy (PAES) of the CuM2,3VV-transition with the unprecedented energy resolution of Δ E E < 1 % . This energy resolution and the highly intense positron source NEPOMUC enabled us to resolve the double peak structure with PAES for the first time within a measurement time of only 5.5 h. In addition, sub-monolayers of Cu were deposited on Fe- and Pd-samples in order to investigate the surface selectivity of PAES in comparison with EAES. The extremely high surface selectivity of PAES due to the different positron affinity of Cu and Fe lead to the result that with only 0.96 monolayer of Cu on Fe more than 55% of the emitted Auger electrons stem from Cu, whereas with EAES the Cu Auger fraction amounted to less than 6%.