ELECTRON-SPECTROSCOPY OF EUROPIUM

Electron emission spectra of Eu, EuAl2 and Eu2O 3 arising from excitation of the europium 4d subshell by 0.5-5 keV electron impact and Al K alpha X-radiation have been compared. The electron-impact-excited emission structure has been assigned primarily to the N45O23O23, N45O23N 67 and N45N67N67 normal Auger transitions and the 4f(4d from 4f) direct recombination process; Auger transitions with a 4, in f spectator electron and the 5p(4d from 4f) direct recombination process appear to be of secondary importance. Europium 4d to 4f giant resonance excitation has been monitored by electron energy loss spectroscopy and correlated with the direct recombination features. The electron emission excited by Al K alpha X-radiation has been shown to be predominantly due to Auger transitions with a spectator vacancy: N45N-NO 23O23, N45N-NO23N67 and N45N-NN67N67. Argon-ion bombardment of europium has been found to excite normal 4d-based Auger electron emission but not direct recombination electron emission.