Transmission Electron Microscopy

TEM instrument

TEM is a microscopy technique in which a beam of electrons is transmitted through a thin specimen, interacting with the specimen as it passes through. An image is formed by detecting the scattered electrons exited the specimen to reveal its internal microstructure. TEM provides morphology and chemical composition of a solid at atomic resolution, as well as its crystal structure. As a key analytical instrument in the physical, chemical and biological sciences, TEM finds wide applications in materials science, pollution, nanotechnology and semiconductor research, as well as cancer research and virology.

LMCC has a FEI Tecnai F20 field emission gun scanning transmission electron microscope.

The 200kV FEI Tecnai F20 Super-Twin is designed to produce high resolution imaging in both TEM and STEM and perform selected area electron diffraction for crystal phase identification. It features a Gatan Orius 2Kx2K CCD delivering high resolution and real time speed for imaging application. This microscope is also equipped with an Oxford Instrument Energy Dispersive X-ray (EDX) spectrometer with 80cm2 sized windowless detector allowing for elemental mapping and line-scan of materials (atomic number Z≥Boron).

Typical industrial uses

Direct imaging of microstructure up to atomic resolution

  • Thin film, epitaxial layer on substrates
  • Semiconductor metrology, superlattice wavelength, layer thickness
  • Interface orientation relationship direct imaging
  • Thickness and composition of deposited coatings
  • Nanoparticles size measurement and distribution
  • Al alloys precipitates hardening process
  • Steels and Ni superalloys carbides distribution

Phase identification

  • Selected area electron diffraction on secondary phases, precipitates
  • Crystal orientation relationship by diffraction

Chemical mapping and line-scan

  • Corrosion and thermal degradation, Grain boundary/interface elemental diffusion
  • Chemical segregation at grain/phase boundary, elemental depletion at grain boundary

In situ TEM imaging

  • Nanoparticles ripening while been heated
  • Interface voids coalescence as a function of heating in vacuum

Key Capabilities

  • High resolution imaging
  • High resolution chemical mapping
  • Secondary phases/precipitates phase identification
  • Crystal orientation relationship by electron diffraction
  • Interface sharpness/cleanness nanoscale imaging and elemental mapping
  • Energy Dispersive X-ray Spectroscopy (EDX)
  • High angle annular dark field imaging (HAADF)
  • MEMS in-situ heating stage

operating a transmission electron microscope

FEI – Tecnai F20 FEGSTEM

Specifications:

  • Electron source: Schottky field emitter with high maximum beam current (> 100 nA)
  • High probe current (0.5 nA or more in 1 nm probe)
  • Imaging: TEM point resolution (0.24nm), Information limit (0.14nm)

Sample holders:

  • FEI Single Tilt Holder +40°
  • FEI Double Tilt Holder +30°
  • FEI in-situ holder: NanoEx-i/v, up to 1200°C

Are you interested in using this technique?

If you are interested in using this technique and would like further information please do not hesitate to get in touch.

Loughborough Researchers Industrial Users / External Researchers