Transmission electron microscopy


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FYS4340

  • FYS4340

    • Theory based on ”Transmission electron microscopy” by D. B. Williams and C.B. Carter
    • Part 1, 2 and standard imaging techniques (part 3)
    • Practical training on the TEM
  • FYS9340

    • Theory same as FYS4340 + additional papers related to TEM and diffraction.
    • Teaching training.
    • Perform practical demonstrations on the TEM for the master students.




Electron microscopy are based on three possible set of techniqes

  • Electron microscopy are based on three possible set of techniqes





The interesting objects for EM is not the average structure or homogenous materials but local structure and inhomogeneities

  • The interesting objects for EM is not the average structure or homogenous materials but local structure and inhomogeneities



1839, George Airy: there should be a natural limit to the optical microscopes.

  • 1839, George Airy: there should be a natural limit to the optical microscopes.

  • 1872, both Ernst Abbe and Hermann von Helmholtz: Light is limited by the size of the wavelength.



1857, The cathode-ray tube was invented

  • 1857, The cathode-ray tube was invented

  • 1896, Olaf Kristian Birkeland experimenting with the effect of parallel magnetic fields on the electron beam of the cathode-ray tub concluded that cathode rays that are concentrated on a focal point by a magnet are as effective as parallel light rays that are concentrated by means of a lens.



1926, Hans Busch, ”Founder of the electron optics” published his theory on the trajectories of electrons in magnetic fields.

  • 1926, Hans Busch, ”Founder of the electron optics” published his theory on the trajectories of electrons in magnetic fields.

  • 1928, Graduate student Ruska worked on refining Busch’s work.

    • The energy of the electrons in the beam was not uniform resulting in fuzzy images.
    • Knoll and Ruska were able design and construct electron lenses and the first realization of an electron microscope.”


1897, J.J. Thomson

    • 1897, J.J. Thomson
      • Concludes that electrons have particle nature.
    • 1924, Louis de Broglie
      • Hypothesis: Matter on the scale of subatomic particles possesses wave characteristics. The speed of low-mass subatomic particles, such as electrons, is related to wavelength .
  • 1927, Davisson and Germer and Thomson and Reid

    • Both demonstrated the wave nature of electrons by independently performing electron diffraction experiments


Knoll and Ruska, first TEM in 1931

  • Knoll and Ruska, first TEM in 1931

  • Idea and first images published in 1932

  • By 1933 they had produced a TEM

  • with two magnetic lenses which gave

  • 12 000 times magnification.



1939 Elmiskop by Siemens Company

  • 1939 Elmiskop by Siemens Company

  • 1941 microscope by Radio corporation of America (RCA)

    • First instrument with stigmators to correct for astigmatism. Resolution limit below 10 Å.


Spherical aberration coefficient

  • Spherical aberration coefficient







1956 independent observations of dislocations by:

  • 1956 independent observations of dislocations by:

  • Hirsch, Horne and Wheland and Bollmann

  • -Started the use of TEM in metallurgy.

  • 1956 Menter observed lattice images from materials with large lattice spacings.

  • 1965 Komoda demonstrated lattice resolution of 0.18 nm.

    • Until the end of the 1960’s it was mainly used to test resolution of microscopes.






Early 1970’s: Development of energy dispersive x-ray (EDX) analyzers started the field of analytical EM.

  • Early 1970’s: Development of energy dispersive x-ray (EDX) analyzers started the field of analytical EM.

  • Development of dedicated HREM

  • Electron energy loss spectrometers and scanning transmission attachments were attached on analytical TEMs.

    • Small probes making convergent beam electron diffraction (CBED) possible.


Development of combined high resolution and analytical microscopes.

  • Development of combined high resolution and analytical microscopes.

    • An important feature in the development was the use of increased acceleration voltage of the microscopes.
  • Development of Cs corrected microscopes

    • Probe and image
  • Improved energy spread of electron beam

    • More user friendly Cold FEG
    • Monocromator


Transmission Electron microscope (TEM)

  • Transmission Electron microscope (TEM)

    • Electron energies usually in the range of 80 – 400 keV. High voltage microscopes (HVEM) in the range of 600 keV – 3 MeV.
  • Scanning electron microscope (SEM) early 1960’s

  • dedicated Scanning TEM (STEM) in 1968.

  • Electron Microprobe (EMP) first realization in 1949.

  • Auger Scanning Electron Microscopy (ASEM) 1925, 1967

  • Scanning Tunneling Microscope (STM) developed 1979-1981

  • Because electrons interact strongly with matter, elastic and inelastic scattering give rise to many different signals which can be used for analysis.



Show both particle and wave properties

  • Show both particle and wave properties

  • Electrons can be accelerated to provide sufficient short wave length for atomic resolution.

  • Due to high acceleration voltages in the TEM relativistic effects has to be taken into account.










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