Knowledge Base

Doublet Separations

• No relevant non-S-orbital emissions

The Energies Listed are Binding Energies!

• O 1s: 530 eV
• O 2s: 20 eV
• O 2p: 8 eV

The Energies Listed are Binding Energies!

Overlaps for O 1s (primary emission)

• Na KLL (Al kα X-rays) (500 eV)
• V 2p (512 eV)
• Dy MNN (Al kα X-rays) (517 eV)
• Sb 3d (528 eV)
• Pd 3d (531 eV)
• At 4d (533 eV)

Energies listed are Kinetic Energies!

O KLL: ~ 505 eV

Oxygen is generally analysed using the O 1s region, which is a typical symmetric Gaussian with no particularly unusual features.

The O 1s core level is particularly significant in XPS analysis because it provides detailed information about the chemical states of oxygen atoms. The binding energy of the O 1s electrons varies depending on the specific chemical environment, allowing for the identification of different oxygen-containing species such as oxides, hydroxides, carbonates, and organic oxygen compounds. Accurate interpretation of the O 1s spectra requires careful consideration of factors such as sample preparation, charge neutralization, and peak fitting, as the O 1s region can be complex with overlapping peaks from different oxygen species.

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If depth profiling metal oxides, be aware that aggressive ion etching treatments will preferentially remove oxygen. Collect the oxygen first for each scan.

Recording an extended range (~580 eV), permits recording of the O 1s loss feature, caused by inelastically scattered electrons – and may be used to measure material band gaps.

If a significant amount of sodium is present, be sure to record at energies up to around 540 eV, as a lower level Auger emission from the Na KLL transition will present as spectral intensity at the high binding energy side – which will need a larger range for correct background modelling.

Oxygen analysed in the presence of Na may result in confusion with some lower order signal intensity from the Na KLL Auger transition – appearing as high energy Oxygen. This may be particularly confusing if analysing O 1s species at very high BE (e.g. water in NAP-XPS), where the Na intensity may seem to be a shoulder of the main peak.

Overlap between O 1s and Na KLL signal – note this Na KLL intensity may be mistaken for high energy O 1s features