Related Experiment Video
Updated: Jun 13, 2025
08:53
Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures
Published on: October 9, 2012
17.6K
Atomic resolution scanning transmission electron microscopy at liquid helium temperatures for quantum materials
Junsik Mun1, Daniel Potemkin2, Houk Jang3
1Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
Ultramicroscopy
|September 14, 2024
Summary
Achieving atomic resolution in low-temperature electron microscopy is now possible by managing helium gas flow noise. This breakthrough enables detailed imaging of quantum materials and devices at liquid helium temperatures.
Area of Science:
- Condensed matter physics
- Materials science
- Electron microscopy
Background:
- Quantum phenomena in condensed matter require low temperatures for observation.
- Atomic resolution scanning transmission electron microscopy (cryo-STEM) is crucial for characterizing quantum materials.
- Challenges in cryo-STEM include sample drift and noise from liquid helium cooling.
Purpose of the Study:
- To demonstrate atomic resolution cryo-STEM imaging at liquid helium temperatures.
- To identify and mitigate noise sources in cryo-STEM.
- To apply advanced imaging techniques to study structural phase transitions in quantum materials.
Main Methods:
- Utilized a commercial side-entry liquid helium cooling holder for STEM.
- Investigated STEM imaging performance versus helium gas flow rate.
- Developed strategies to reduce noise, including suppressing gas flow and imaging during warming.
- Applied image processing techniques to analyze structural phase transitions.
Main Results:
- Identified helium gas pulsing and bubbling as primary noise sources.
- Demonstrated that suppressing helium gas flow or imaging during warming significantly reduces noise.
- Successfully applied the methods to image structural phase transitions in Cr2Ge2Te6, CuIr2S4, and CrCl3.
Conclusions:
- Atomic resolution cryo-STEM imaging at liquid helium temperatures is achievable with optimized helium gas management.
- The developed techniques enhance the characterization of quantum materials and devices.
- These findings advance electron microscopy capabilities for low-temperature quantum material research.
Related Concept Videos
01:15Transmission Electron Microscopy
5.4K
In 1931, physicist Ernst Ruska—building on the idea that magnetic fields can direct an electron beam just as lenses can direct a beam of light in an optical microscope—developed the first prototype of the electron microscope. This development led to the development of the field of electron microscopy. In the transmission electron microscope (TEM), electrons are produced by a hot tungsten element and accelerated by a potential difference in an electron gun, which gives them up to 400...
5.4K
01:25Overview of Electron Microscopy
8.6K
The wavelengths of visible light ultimately limit the maximum theoretical resolution of images created by light microscopes. Most light microscopes can only magnify 1000X, and a few can magnify up to 1500X. Electrons, like electromagnetic radiation, can behave like waves, but with wavelengths of 0.005 nm, they produce significantly greater resolution up to 0.05 nm as compared to 500 nm for visible light. An electron microscope (EM) can create a sharp image that is magnified up to 2,000,000X.
8.6K
01:28Cryo-electron Microscopy
3.3K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
3.3K
01:07Scanning Electron Microscopy
4.2K
A scanning electron microscope (SEM) is used to study the surface features of a sample by using an electron beam that scans the sample surface in a two-dimensional manner. Typically, areas between ~1 centimeter to 5 micrometers in width can be imaged. SEM can be used to image bacteria, viruses, tissues as well as larger samples like insects. Conventional SEM gives a magnification ranging from 20X to 30,000X and spatial resolution of 50 to 100 nanometers.
Fundamental Principles
Accelerated...
Fundamental Principles
Accelerated...
4.2K
01:07Electron Microscope Tomography and Single-particle Reconstruction
2.4K
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
2.4K
01:20Preparation of Samples for Electron Microscopy
5.4K
To be visualized by an electron microscope, either transmission or scanning, biological samples need to be fixed (stabilized) so the electron beam does not destroy them and dried thoroughly (desiccated/dehydrated) so the vacuum does not affect them. Fixation needs to be done as quickly as possible because the sample properties will start changing as soon as it is removed from its natural environment. For example, in a tissue sample, the oxygen levels begin decreasing, causing an altered...
5.4K