This document discusses X-ray photoelectron spectroscopy (XPS), a technique used to analyze the surface chemistry of materials. XPS uses X-rays to excite photoelectrons from the top 1-10 nm of a sample, and measures their kinetic energy to determine the elemental composition, empirical formula, chemical and electronic states. It works by relating the photoelectrons' binding energy to the energy of the exciting X-ray photons minus the kinetic energy and work function. XPS can identify all elements except hydrogen and helium, and is useful for quantifying elemental composition and chemical bonding at surfaces.

1. ADVANCED MEDICAL
INSTRUMENTATION
X-RAY PHOTOELECTRON
SPECTROSCOPY
BY – UZMA S. MHATE
BBE - 15007

2. WHAT IS SPECTROSCOPY?

3. WHY STUDY X-RAY
PHOTOELECTRON
SPECTROSCOPY?

4. PRINCIPLE OF XPS

5. ABOUT X-RAY PHOTOELCTRON SPECTROSCOPY…
• Also known as ‘Electron
Spectroscopy for Chemical
Analysis (ESCA)’.
• Used to measure elemental
composition (Armstrong
range), empirical formula,
chemical state, electronic
state of elements within the
sample.
• Measures kinetic energy and
escaping electrons under
Ultra High Vacuum.

6. …
• XPS can measure elements
having atomic number of Li (Z =
3) and above.
• Not preferred to measure
hydrated forms due to an ice
layer forming in ultra-high
pressure.
• XPS detects only those electrons
that have actually escaped from
sample to the vacuum of
instrument.
Eb = Ephoton – Ek – W
Eb = Binding Energy
Ephoton = Energy of X-ray
Ek = Kinetic energy
W = Work Function

9. • Different elements have different Binding Energies which are
used to identify the elements, chemical bonds and ligands.
• The curve illustrates quantification of number of electrons (X-
axis) to the Binding Energies (Y-axis).
• Binding energy is in eV.
• Ultra high vacuum is maintain to minimize the errors.

11. REFERENCE
Khandpur- Handbook of Biomedical Instrumentation
Wikipedia.com
www.researchgate.net

12. THANK YOU…