Advances in Auger spectroscopy by density functional theory calculations


Gian Paolo Brivio

ETSF, CNISM, Dipartimento di Scienza dei Materiali, UniversitÓ di Milano-Bicocca, Milano (Italy).


Thursday, 16 September 2010, 13:15
Matfys library

Abstract:
New interest in Auger decays is motivated by first principle calculations coupled to synchrotron radiation refined measurements. In this talk we focus on two topics of Core-Valence-Valence (CVV) transitions, which are computed in the two step approximation with the golden rule within a density functional theory (DFT) framework. First we address the problem of the hole-hole interaction in closed valence shell systems by using Janak's theorem to compute the screened hole-hole interaction U as input for the Cini-Sawatzki model. Comparison of the calculated spectra with experiments is performed for Zn and Cu [1]. Second we deal with spin polarization of the Auger electrons for 3d impurities in simple metal hosts and derive a simple but general expression which allows one to determine the impurity magnetic moment from the spin polarization of the emitted electron [2]. Finally angular dependence and spin polarization in coincidence experiments between the photo- and the Auger-electrons are discussed.

1.G. Fratesi, M.I. Trioni, G.P. Brivio, S. Ugenti, E. Perfetto and M. Cini: On the ab initio calculation of CVV Auger spectra in closed shell systems, Phys. Rev. B 78, 205111 (1-9), (2008).

2.M.I. Trioni, A. Zanetti, G. Fratesi and G.P. Brivio: Spin polarized Auger electrons in Core-Valence-Valence decays of 3d impurities in metals, Phys. Rev. B 79, 165115 (1-7) (2009); Phys. Rev. B 79, 079901 (E) (1,2) (2010).