Peculiarities of the Cu LVV Auger line in copper oxide cuprates and HTSC-materials studied by x-ray photoelectron and Auger electron spectroscopies

Abstract

Auger electron spectroscopy investigations of various copper compounds, including oxides, cuprates and high-temperature superconducting (HTSC) YBaCuO-type materials, show that the linewidth of the Cu LVV transition for these compounds increases with the oxygen-to-copper ratio. Correspondingly, for the same compounds, the intensity ratio of the satellite (Is) and main (Im) lines in the Cu 2p3/2 line measured from XPS spectra decreases. Taking into account the mechanisms of Auger electron and x-ray photoelectron transitions, this correlation may be explained by an increase in the probability of electron transition from the O 2p to Cu 3d level in cuprates when compared with CuO. The peculiarities of Auger spectra found for YBa2Cu3O6.6–6.9 and for cuprates may be used to evaluate the quality of HTSC films by Auger microprobe.