X-ray photoemission study of yttrium contained in radiotherapy systems

Abstract

X-ray photoelectron spectroscopy was used to obtain information on yttrium local atomic arrangement and electronic structure in Y2O3-Al2O3-SiO2 glass system doped up to 1 mol % with Fe2O3. Both Y 3p and Y 3d core level photoelectron peaks are influenced by iron addition to yttrium alumino-silicate host glass and evidence spin orbit splitting. The positions of the photoelectron peaks are shifted to some higher energies relative to pure yttrium. This is correlated with fact that the effective electronic charge density on the yttrium cations decreases as the number of oxygen anions increases. The decrease in effective electronic charge density around yttrium would be reflected in an increase in the binding energy of the remaining electrons.