General information

• Investigation area

  3D Materials Analytics
• Techniques

  Atom Probe Tomography
  
• Manufacturer

  Cameca
• Fabrication year

  2021
• Measured quantity

  Chemical composition, with no lower or upper limits of elemental mass, within samples with a typical size of 100 x 100 x 500 nm
• Main application

  3D compositional mapping with a sub-nanometer resolution and high sensitivity (ppm)

Instrument specification

• Technical aspects

  Our LEAP 5000 XR atom probe tomography equipment enables the quantitative analysis of local chemical composition at the sub-nanometer scale with a sensitivity in the range of ppm. All elements can be detected with the same efficiency, including light elements such as hydrogen, carbon or lithium. The achieved mass resolution is sufficient to distinguish each isotope of each of the detected elements. Our APT is equipped with a reflectron, that bends the ion trajectories, thereby offering the possibility to extend the time of flight of the ions and improve the relative precision of the measurement and the mass resolution.

  The method: APT is underpinned by the field evaporation of surface atoms of a needle-shaped specimen with a radius of curvature of approximately 100 nm. It is therefore a destructive technique. Each atom is desorbed and ionized one by one using high voltage or laser pulses, in addition to the direct current (DC) voltage. Then, the elemental nature of each ion detected is identified thanks to a time-of-flight spectrometer, and coupled to its own impact position, allowing us to generate a 3D point cloud that reveals the solute distribution in 3D.

  Sample type and preparation: APT can be used to characterize all conductive and semi-conductive samples. In the latter, a pulsed-laser beam is focused towards the specimen apex. In our lab, we analyze steels, aluminum alloys for aerospatial applications, cupper alloys for microelectronics applications, and more.

  Sample size and geometry: Samples needs to be in the shape of a needle, with a sharp apex (radius of curvature below 100 nm). The samples can be prepared using electropolishing or by focused ion beam (FIB). The size of the analyzed volume is typically 100 x 100 x 500 nm3.    

• Additional measurement possibilities

  APT is ideally suited to complement electron-based or X-ray-based microscopies and spectroscopies. A cryogenic ultra-high-vacuum transport module (VCTM) is also installed to transfer samples from the SEM-FIB to the APT in a protected environment, in order to avoid any contamination from the ambiant air and/or increase in temperature of the specimen.

Contact

• Application scientist

  Belkacemi, Lisa
  , IWT
  FZB 1140 Leibniz-Institut für Werkstofforientierte Technologien
  Phone number 0421 218 51372
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• Jérémy Epp
  , IWT
  
  Phone number 0421 218-51335
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• Principal investigator

  Rainer Fechte-Heinen
  

Instrument location

• Building

  IW 1/2
• Room

  0090
• Faculty

  --
• Institute

  IWT