Singularities in the auger emission spectrum of metals

Singularities in core-level spectra near metallic surfaces

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] Relaxation shifts due to several screening mechanisms, [10][11][12][13][14][15][16][17][18][19] chemical shifts, 12,19 satellite peaks due to multiple plasmon or electron-hole pair excitations, 3,6,7 and finally the deviations from the standard line shapes, provide a wealth of information characteristic for specific core levels and their interaction with the environment. 12,14 It is well known that in metals the excitation of multiple soft electron-hole pairs near the Fermi surface leads to singularities in the low-energy part of the photoelectron spectrum and to the characteristic asymmetric line shapes.…”

“…It should be emphasized that, while the neglected class of processes is usually unimportant in XPS, analogous processes are essential for the proper description of x-ray absorption and emission 2,4,7,22 and Auger emission. 8 If we define the exact response function of the metallic electrons ͑Fig. 3͒ as the solution of the integral equation ͑r 1 ,r 2 ,t 1 ,t 2 ͒ = ͟ ͑r 1 ,r 2 ,t 1 ,t 2 ͒ + ͵ drdrЈ ͵ dt ͟ ͑r 1 ,r,t 1 ,t͒ ϫv͑r,rЈ͒͑rЈ,r 2 ,t,t 2 ͒, the cumulant sum in Fig.…”