Histogram Plots of XPS BEs

Histogram Plots for XPS BEs measured
from Elements and compounds

NOTE: NIST HAS NEVER MEASURED any XPS BEs

from any pure metal, pure element, pure oxides, pure polymer
or any chemical compound listed in the NIST Collection

All 25,000+ XPS BEs were extracted from hundreds of OLD literature
publications by Dr. Charles D. Wagner at U Cal Berkeley)

We Recommend: Use NIST XPS BEs ONLY as a Guide

Examples of Histogram Plots o XPS BEs

Silver Metal, Ag	Gold Metal, Au	Copper Metal, Cu

Histogram Plots Reveal Validity and Reliability,
and produce useful “Mean BEs” Values

BEs listed in the NIST database were collected over many years time by many different analysts operating many different XPS instruments who used:

different BE Calibration Values
- Cu (2p3/2) BE ranged from 932.2 eV to 932.8 eV (a 0.6 eV range)
different Separation in Calibration Values (SCE)
- separation values between Cu (2p3/2) and Au (4f7/2) ranged from 848.0 eV to 849 eV (a 1.0 eV range)
different Carbon (1s) BEs for hydrocarbon type adventitious carbon
- C (1s) BE ranged from 284.2 eV to 285.2 eV (a 1 eV range)
different frequency to check BE Calibration Values, or never checked

Therefore, some of the BE values from pure conductive elements have large BE ranges, as large as 1 eV. Non-conductive chemical compounds have much larger BE uncertainties because C (1s) was used to charge reference non-conductors, and also due to differential charging effects. Due to the use of different Cu (2p3/2) BEs for calibration at the high BE end, you will find increasing larger errors or uncertainties in BEs above 600 eV due to the ever increasing scaling difference as you go from o eV to 1,480 eV.