PUNJAB ENGINEERING COLLEGE: CHANDIGARH
(DEEMED TO BE UNIVERSITY)
Tute Sheet 2
Programme: B.E. (All branches) Year/Semester: 25-26/Ist
Course: Advanced Instrumentation Methods of Analysis Course Code: CH6001
Q1. Explain the Auger process with the help of an energy level diagram. What conditions must be
satisfied for an Auger electron to be emitted?
Q2. Describe the difference between primary electrons and Auger electrons. How does the Auger
process occur following the creation of a core hole?
Q3. Why is AES considered a surface-sensitive technique? Discuss the factors that determine
the escape depth of Auger electrons.
Q4. A clean metal surface is exposed to a gas. After exposure, new peaks appear in the AES
spectrum.
(a) How can AES be used to identify the adsorbed species?
(b) What are the limitations of AES in quantifying surface coverage?
Q5. Compare the spatial resolution of AES with that of XPS. In what scenarios would AES be
preferred?
Q6. Derive the equation for the binding energy of a photoelectron detected in XPS. Define each
term.
Q7. Given an X-ray source of 1253.6 eV and a detected kinetic energy of 935.2 eV for a
photoelectron, calculate the binding energy if the spectrometer work function is 4.2 eV.
Q8. Why is XPS a surface-sensitive technique despite the high energy of X-rays used?
Q9. Discuss how XPS can be used to determine the oxidation state of a metal in a compound. Give
an example using Fe or Cu.
Q10. Compare and contrast XPS and AES in terms of: Depth of analysis & Sensitivity to elements.
