Below is a list of some of the XPS experimental details that may be needed for most scientific publications. Beside each detail are some examples of what could be used or stated.
1) Instrument Name: Kratos Axis Supra, Kratos Axis Nova, Surface Science Laboratories SSX-100, PHI Quantera, PHI VersaProbe, VG ESCALAB 250, type of energy analyzer etc.
2) X-ray Source: monochromatic Al K(alpha) at 1486.6 eV, non-monochromatic Mg K(alpha), Zr L, He(I), He(II), synchrotron tunable source set at ‘x’ kV
3) X-ray Power: 15 mA and 15 kV, 225 W (= 15mA x 15 kV)
4) Spectrometer Calibration Details: The instrument work function was calibrated to give a binding energy (BE) of 83.96 eV for the Au 4f7/2 line for metallic gold and the spectrometer dispersion was adjusted to give a BE of 932.62 eV for the Cu 2p3/2 line of metallic copper.
5) Spot Size, Area of Analysis, Angle: 300x700 micron area of analysis, 300 micron spot, small spot analysis using a 55 micron spot size, 90 degree take-off angle / 0 degree of sample tilt, angle resolved analysis
6) Charge Neutralizer Use: The Kratos magnetic confinement charge compensation system was used on all samples (One may also want to include charge neutralizer settings although this can vary depending on the age of the filament, contamination of the charge plates etc. A note on the how good charge neutralization was deemed to have occurred may suffice). An electron flood gun at ‘x’ settings.
7) Effectiveness of Neutralizer: Charge neutralization was deemed to have been fully achieved by monitoring the C 1s signal for adventitious carbon. A sharp main peak with no lower binding energy structure is generally expected.
8) Charge Correction Procedures: Spectra have been charge corrected to the main line of the carbon 1s spectrum (adventitious carbon) set to 284.8 eV (or 285.0 eV for polymer samples), Au 4f7/2 at 83.96 eV, no charge correction (conductive samples)
9) Instrument Base Pressure: 8 x 10-10 Torr.
10) Scan Details, Pass Energy, Number of Sweeps, Step Size, Scan Window: The C 1s spectra were taken with a minimum of 10 - 60s scans with a scan window of 278-295 eV using a 0.05 eV step and 20 eV pass energy.
11) Spectrometer Resolution Details: Ag 3d5/2 line FWHM at 10 eV pass energy was 0.48 eV. Source resolution for monochromatic Al K(alpha) X-rays is ~0.3 eV. The instrumental resolution was determined to be 0.35 eV at 10 eV pass energy using the Fermi edge of the valence band for metallic silver. Resolution with charge compensation system on <0.68 eV FWHM on PET.
12) Sample Mounting Details: held by metal clips and grounded to the holder, mounted on double sided adhesive tape, electrically isolated from the sample holder
13) Software Used for Curve-Fitting: CasaXPS version (2.3.26), XPSPeak, Vision 2 Processing Software, Avantage
14) Line-shape Details: 50% Gaussian/50% Lorentzian, Asymmetric line-shape defined by…,
15) Background Used for Curve-Fitting: Shirley, Linear, Tougaard
16) Other Curve-Fitting Details as Needed: FWHM, constraints, doublet separations
A recent article from Pinder et al.[1] discusses a similar list as above for reporting instrument parameters. They also discuss common errors seen in XPS publications, well worth a read as a quality check prior to publishing your own data.
Reference:
[1] J.W. Pinder, G.H. Major, D.R. Baer, J. Terry, J.E. Whitten, J. Cechal, J.D. Crossman, A.J. Lizarbe, S. Jafari, C.D. Easton, J.Baltrusaitis, M.A. van Spronse, M.R. Linford, Appl. Surf. Sci. Adv., 19 (2024) 100534.
