Lecture

Transmission electron microscopy

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Description

This lecture covers the application of transmission electron microscopy (TEM) in the analysis of dislocations, focusing on 3D reconstruction techniques, chemical analysis, and image processing. Topics include dislocation visualization, tomography, CNN-based reconstruction, synthetic dataset simulations, and spectral analysis. The instructor presents case studies on mineral assemblages, PCA decomposition for phase contrast, and NMF for spectral analysis. The lecture also discusses the challenges of self-absorption effects, detector efficiency, and creating artificial datasets for TEM analysis.

Official source

Related concepts (32)

Transmission electron cryomicroscopy

Transmission electron cryomicroscopy (CryoTEM), commonly known as cryo-EM, is a form of cryogenic electron microscopy, more specifically a type of transmission electron microscopy (TEM) where the sample is studied at cryogenic temperatures (generally liquid-nitrogen temperatures). Cryo-EM is gaining popularity in structural biology. The utility of transmission electron cryomicroscopy stems from the fact that it allows the observation of specimens that have not been stained or fixed in any way, showing them in their native environment.

Scanning transmission electron microscopy

A scanning transmission electron microscope (STEM) is a type of transmission electron microscope (TEM). Pronunciation is [stɛm] or [ɛsti:i:ɛm]. As with a conventional transmission electron microscope (CTEM), images are formed by electrons passing through a sufficiently thin specimen. However, unlike CTEM, in STEM the electron beam is focused to a fine spot (with the typical spot size 0.05 – 0.2 nm) which is then scanned over the sample in a raster illumination system constructed so that the sample is illuminated at each point with the beam parallel to the optical axis.

Cryogenic electron microscopy

Cryogenic electron microscopy (cryo-EM) is a cryomicroscopy technique applied on samples cooled to cryogenic temperatures. For biological specimens, the structure is preserved by embedding in an environment of vitreous ice. An aqueous sample solution is applied to a grid-mesh and plunge-frozen in liquid ethane or a mixture of liquid ethane and propane. While development of the technique began in the 1970s, recent advances in detector technology and software algorithms have allowed for the determination of biomolecular structures at near-atomic resolution.

Transmission electron microscopy

Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a sensor such as a scintillator attached to a charge-coupled device.

Electron microscope

An electron microscope is a microscope that uses a beam of electrons as a source of illumination. They use electron optics that are analogous to the glass lenses of an optical light microscope. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light, electron microscopes have a higher resolution of about 0.1 nm, which compares to about 200 nm for light microscopes.

Related lectures (64)

High Resolution TEM: Imaging and Contrast

Explores High Resolution TEM principles for atomic-level crystal imaging.

Transmission Electron Microscopy: Advanced Techniques MOOC: Transmission Electron Microscopy for Materials Sciences

Explores advanced techniques in transmission electron microscopy, focusing on phase contrast imaging and camera settings.

Imaging modes in TEM

Explores imaging modes in TEM, covering electron-matter interactions, diffraction patterns, image formation, contrast principles, and detector configurations.

Dynamical Effects: Thickness Fringes MOOC: Transmission Electron Microscopy for Materials Sciences

Delves into the dynamical scattering effect of thickness fringes in TEM images, covering equations, intensity plots, and weak beam imaging.

Electron Microscopy: TEM

Explores Transmission Electron Microscopy (TEM), covering diffraction patterns, image formation, and contrast mechanisms.

Related concepts (32)

Transmission electron cryomicroscopy

Scanning transmission electron microscopy

Cryogenic electron microscopy

Transmission electron microscopy

Electron microscope