The peak tables of XPS provided the two surface elemental distribution: Atomic % and PP At.%. The "Atomic %" is the origin one while the "PP At. %" is the one calculated from the data substrate a baseline? The PP At. % is more reliable?
Please cite the reference where this information is shown. Or state what explanation is given with the tables of information.
I suspect the pp at% is determined from peak height. If so, it is less accurate.
Yifeng, you can find PP in Thermo Avantage Help file.
Peak To Peak Quantification
Peak to peak quantification is usually performed on first derivative spectra. The Peak Table has additional columns labelled PP Height, PP Hgt (N) normalised intensity and PP At %, to allow these measurements to be made. The PP Height is defined as the difference between maximum intensity and minimum intensity within the defined energy range. It is recommended that spectra are differentiated and then peaks are added using Add Peak. It is also recommended that mixed quantification of normal and differentiated data is not performed.
Note that when data has been differentiated, the Peak Area, Normalised Peak Area and At % (based on Peak Area) are disabled.
The PP columns entries are present on normal (non-differentiated) data and non-differentiated data.
Non-Linear Least Squares Fitting may also be performed on derivative spectra.
PP means Peak To Peak
In X-ray Photoelectron Spectroscopy (XPS) analysis, both Atomic % (atomic percent) and Peak-to-Peak Atomic % (peak-to-peak atomic percent) are quantitative measures used to determine the elemental composition of a material's surface. However, they represent slightly different aspects of the data:
Atomic % (Atomic Percent):
- Atomic percent represents the proportion of a specific element's atoms relative to the total number of atoms detected at the surface of the material.
- It is calculated by dividing the number of atoms of a specific element by the total number of atoms detected in the XPS analysis.
- Atomic % provides information about the overall elemental composition of the surface.
Peak-to-Peak Atomic % (Peak-to-Peak Atomic Percent):
- Peak-to-peak atomic percent is a more specific measurement that focuses on the relative concentration of an element within a particular chemical state or peak in the XPS spectrum.
- It is calculated by comparing the area under the peak corresponding to a specific chemical state or element to the total area under all the peaks in the XPS spectrum.
- Peak-to-peak atomic % provides information about the distribution of a specific element among different chemical states or environments on the surface.
Both atomic % and peak-to-peak atomic % are used to quantify the elemental composition of a material's surface in XPS analysis, atomic % gives you the overall composition, while peak-to-peak atomic % provides information about the distribution of an element among different chemical states or peaks in the XPS spectrum. The choice between the two depends on the specific information you are seeking about the material's surface properties.