Devaluation of the gold standard in x-ray photoelectron spectroscopy

The value of vapor-deposited gold as a standard in x-ray photo-electron spectroscopy has been studied. During the deposition gold may react with the sample giving consequent shifts and/or broadening of the Au 4f peaks. Shifts to higher binding energies have been observed with KCN and NACl and to lower energies with Na₂S₂O₃ and copper phthalocyanine. The An 4f peaks have been investigated over the temperature range ?50 to 200°C. At higher temperatures peaks due to metallic gold are observed. Anomalous effects have been observed in the XPS spectrum of gold plated copper phthalocyanine in the binding energy range 650–950 eV.