Thermo K-alpha XPS

Chemical Analysis of Solids and Powders

The Thermo K-Alpha XPS uses a focused beam of x-rays to eject electrons from the near-surface region of a sample in a vacuum.

The energies of those electrons are characteristic of the elements from which they came and the specific chemical bonds that involve those elements.

By plotting the number of photoelectrons as a function of energy, one can obtain detailed information on the near-surface elemental and chemical composition of a sample.

To reserve time or request training on this tool, click here or on the image at left to go to the K-alpha XPS tool page on SUMS.

Deconvolution of Carbon spectrum in a graphene oxide film on SiC shows XPS ability to distinguish chemical states. Nitrogen-rich areas -in Red on map above – show amine-terminated spots on a Ti layer.  The map is overlaid on an optical image of the sample.  An integrated Ar sputter gun allows in-situ sample cleaning and depth profiles like the one above on a multi-layer PZT film.

 

Several analysis techniques provide information about elemental composition (XRF, EDS, SIMS, etc.).  For inorganic compounds that information is usually enough to determine a sample’s chemical makeup.  However, for organic compounds, there are typically numerous chemical permutations even within the constraints of a given composition.

Only a few techniques provide direct evidence of the chemical state of an element.  Among them, XPS is unique in it’s surface sensitivity, which makes it an ideal way to study – among other materials – (catalysts, ion-exchange membranes, graphene and other low-dimensional structures, functionalized CNT’s, metal corrosion, etc.)
System Details:

Sources:

  • X-ray source:  Monochromated Al Kα radiation; Microfocused to a spot with diameter selectable between 30 and 400 μm
  • Flood gun:  Integrated mixed low-energy electron and Ar-ion gun for charge compensation
  • Sputter gun:  Ar+ ion gun; Ion energy selectable from 200 to 3000 eV.
  • Analyzer:  Hemispherical analyzer with MCP detector; Pass energy range from 20 to 250 eV for high-resolution and wide range survey spectra, respectively

Capabilities:  Single-point spectra;  Line profiles; Area Chemical Maps; Depth Profiles

  • Samples:  Special vacuum-sealed stage for air-sensitive samples; interchangeable plates for flat and powder samples

 

Files:

K-alpha XPS Instructions

K-Alpha Depth Profile Instructions

K-Alpha Chemical Mapping Instructions

K-Alpha XPS Sputter rate calculator