Method of electron diffraction tomography
AssigneeFEI Company
InventorsHaifeng He, Andreas Voigt
Life of this patent
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Abstract
The invention relates to a method for electron diffraction tomography in a Transmission Electron Microscope. Known methods involve using Scanning Transmission Electron Microscope, and use the scanned beam for STEM diffraction. The invention proposes to form the diffraction patterns with a stationary beam with a diameter slightly larger than the crystal, as a result of which a TEM without STEM unit can be used. Finding the crystal is done in TEM mode. Advantages of the method according to the invention are: a TEM without scanning unit can be used, and the diffraction volume is not depending on the orientation of the crystal, as the whole crystal is illuminated while obtaining the diffraction pattern.
Claims17
A method of determining the crystallographic structure of a crystal by electron diffraction tomography using an electron microscope, the electron microscope equipped to irradiate the crystal with a beam of electrons, the method comprising:
- providing a sample with one or more crystals therein,
- identifying a crystal to be analyzed on the sample,
- recording a diffraction tilt series of the crystal by repeatedly tilting the sample to a known tilt angle with respect to the beam,
- centering the crystal with respect to the beam, and
- recording a diffraction pattern of the crystal at said tilt angle, and
- determining the crystallographic structure by analyzing the recorded diffraction patterns,
- in which while recording the diffraction image, the beam is kept stationary with respect to the crystal, and the beam has a diameter larger than the diameter of the crystal.
Dependencies are inferred from the claim text.