Emission of correlated electron pairs from Au(111) and Cu(111) surfaces under low-energy electron impact: Contribution of surface states, d-states and spin effects

• Published in: Journal of electron spectroscopy and related phenomena Vol. 198; pp. 26 - 30
• Main Authors: Samarin, S., Artamonov, O.M., Guagliardo, P., Pravica, L., Baraban, A., Schumann, F.O., Williams, J.F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2015
• Subjects: Correlation; Correlation analysis; Electron impact; Emission spectroscopy; Energy conservation; Excitation; IMPACT PROPERTIES; Low energy; Spectra; Spin-polarized electrons; Surface states; Two-electron spectroscopy; Spin-polarized electrons; Two-electron spectroscopy; Surface states
• ISSN: 0368-2048; 1873-2526
• DOI: 10.1016/j.elspec.2014.11.007

•Spin-polarized two-electron spectroscopy (e,2e) was applied for studying surface states on Cu(111) and Au(111).•Relative (to d-states) contribution of surface states in the (e,2e) spectrum decreases exponentially when primary electron energy increases from 14 to 30eV.•Spin asymmetry is readily observed in the spectra of Au(111) whereas in the spectra of Cu(111) the spin effect is negligible. The emission of correlated electron pairs excited from surfaces of Au(111) and Cu(111) by low-energy electrons is measured and analyzed. Energy and momentum conservation allows identification of electron pairs involving excitation of electrons from Shockley surface states and from valence d-states. The relative contributions of surface and d-states to the measured spectra of correlated electron pairs is shown to depend on the primary electron energy and is larger from surface states at relatively small primary energies. The use of a spin-polarized incident electron beam highlights the spin effects in producing an electron pair. Measurements show that spin effects are larger for the pair excitation from the valence d-states than for pairs excited from the surface states.