Kratos Axis Ultra XPS
Location: 426 Space Research Building
Contact: John Mansfield, Kai Sun, or Haiping Sun
Instructions: EMAL Axis Ultra XPS PDF Handbook and Axis Ultra XPS PDF Manual from Kratos
Acknowledgments: Publications resulting from work on this instrument should acknowledge the support of NSF grant #DMR-0420785.
X-ray Photoelectron Spectroscopy: X-ray Photoelectron Spectroscopy (XPS), also known as Electron Spectroscopy for Chemical Analysis (ESCA), uses soft X-rays to produce photoelectrons from the surface layers of atoms in a solid sample. The emitted electrons are analyzed according to their kinetic energy and the spectrum so produced is used to identify the elements present and their chemical states.
Applications
- Study surface chemistry of different materials, including valence states, composition, and element distribution and element depth profile.
X-ray Sources
- Monochromatic Al source, Al and Mg regular sources.
Operating Conditions
- Spectrum mode:~ 10mA ~ 15kV.
- Parallel XPS imaging.
Vacuum System
- Specimen Transfer Chamber (STC): <5 x 10e-7 torr.
- Specimen Analysis Chamber (SAC): ~1 x e-9 torr.
Specimen Stage
- Motorized sample movement in x,y,z directions and tilting.
- Can be operated at ~600 degree C to -100 degree C.
Analysis Area
- Spectrum mode: Using the monochromated Al source: 2 x 1 mm with energy resolution ~0.5ev.
- Small area spectroscopy: ~ several µm.
- Imaging mode: ~ 900µm x 900µm with spatial resolution ~ 6µm.
Detector System
- Delay Line Detector (DLD) - 2D Detector.
Computer System
- Windows XP with Unix emulator to run acquisition package.
Accessories
- Ar ion sputtering.
- Optical microscope.
- Reaction chamber: ~600°C.
Sample Requirements
- Sample bar is about 12cm long and 1.5cm wide. Sample size should be smaller that 2cm in diameter/square and no more than 2mm thick.
- Sample stub is about 1.5cm in diameter that is mainly used for holding powder samples.
- Thicker samples can be accommodated in alternate sample holders but must be less than 8mm x 15mm and less than ~10mm thick.
- Samples smaller than 5mm diameter are not recommended.
- Sample can be power or solid bulk materials.
- Samples must be compatible with high vacuum, i.e. clean and dry.
- Powder samples must be compacted into a pellet, pounded into soft Indium metal, or otherwise secured to the holder using conductive copper or carbon tapes provided by EMAL.
References
- Example XPS data.
- Table of peak positions and sensitivity factors.
- High Resolution XPS spectra of polymer samples (from Kratos Analytical).
- EMAL has a site-license for CasaXPS. This is off-line analysis software for XPS spectra and images. It is licensed for use on the UM campus. Those users wishing to use it should download it from the CasaXPS site. To determine the download URL, and obtain the license information, send email to John Mansfield.
- There is a web-based manual for CasaXPS.
Flash Animations
Lindsay Shuller, a graduate student in the