Argon cluster source preferred for depth profiling of polymers.Charge neutralization will be required.Good method for analyzing self-assembled monolayers.Statistics) but the amount of X-ray damage at each individual is negligible. Overall acquisition time is then the sum of every point (giving good signal-tonoise.If the sample surface is chemically uniform, it may be preferable to rapidly acquire dataįrom many points and then integrate the data post-acquisition.Acquire regions of interest first (e.g., C1s, O1s) before running survey, if possible.C1s regions for polymers can often have acquisition times of Different polymers have different degradation rates.Some polymers are sensitive to prolonged X-ray exposure.Particularly useful in cases where C1s XPS data cannot easily distinguish between.Acquisition of valence band can be useful for “fingerprint” identification of polymers.Polymers Binding energies of common chemical states: Inelastic scatter of electrons through the adventitious carbon layer may cause a largeĬhange in background shape when compared with the spectrum from a clean sample.For example, the Na1s peak (binding energy=1071eV) may be weaker thanĮxpected, or completely disappear, but the Na KLL peak (binding energy=497eV).The intensity of higher binding energy peaks may be reduced relative to their.Quantification may be inaccurate when using peaks of significantly different energy.On native oxide of aluminium appears at ~286eV).Ī few nanometers of adventitious carbon on a sample can dramatically affect the survey Not always a valid charge reference value (e.g.The C-C component may be set to a binding energy of 284.8eV, by default.C1s spectrum for contamination typically has C-C, C-O-C and O-C=O components.Prevent/minimize chemical damage to the underlying material.Īdventitious carbon contamination is commonly used as a charge reference for XPS spectra. Use lowest energy argon beam available (e.g.Adventitious carbon may be removed by argon sputtering.
(Typically with a layer thickness of 1-2nm.) Most samples that have been exposed to the atmosphere will have a detectable quantity ofĪdventitious carbon contamination.
Carbonates and Carbides)Īdventitious Carbon Contamination Binding energies of common chemical states:Ĭharge referenced to adventitious C1s, C-C peak at 284.8eV Experimental Information
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