Synopsis: Getting More out of Electron Microscopy

A new analysis technique allows researchers to extract atomic-resolution holographic images of materials using a transmission electron microscope.
Synopsis figure
J. Barthel/Jülich Research Center

With transmission electron microscopy (TEM), researchers can visualize the atomic structure within a material. Conventional TEM methods, however, often lose valuable phase information that could provide an even more detailed picture of the sample. Now researchers have demonstrated a TEM technique that can recover all available sample information at atomic resolution. The technique could offer researchers a chance to study the electrostatic potential around defects, for example.

Achieving atomic resolution with TEM is challenging, as deflections (aberrations) in the electron paths can distort the images. The sample information can be recovered by using so-called forward modeling, which involves numerically simulating TEM data. Up until now, these simulations have only been achieved for conventional TEM images, in which valuable phase information is missing.

To exploit all of the TEM information, Florian Winkler from the Jülich Research Center in Germany and colleagues devised an automated forward-modeling technique for off-axis electron holography, in which the microscope’s electron beam is split and then recombined to produce an interference pattern. The team’s technique compares holography data to simulations that account for both material properties and microscope characteristics. The simulation’s parameters are then adjusted to give the best fit to the observations. Because the fit is determined directly from the images, the protocol avoids previous problems stemming from time-varying microscope characteristics. As a demonstration, the team performed electron holography on a tungsten diselenide sample and showed that their technique could pick out a small bending of the crystal structure, as well as spatial variations in the aberrations across the image.

This research is published in Physical Review Letters.

–Michael Schirber

Michael Schirber is a Corresponding Editor for Physics based in Lyon, France.


Features

More Features »

Subject Areas

Materials ScienceCondensed Matter Physics

Previous Synopsis

Related Articles

Focus: Friction Remembers Its Origins
Materials Science

Focus: Friction Remembers Its Origins

Experiments show that the friction between two surfaces depends on their history of contact and that this “memory” is reminiscent of the behavior of glasses. Read More »

Viewpoint: Electrons Film Phonon Dynamics in Full
Materials Science

Viewpoint: Electrons Film Phonon Dynamics in Full

An electron-scattering technique with femtosecond resolution can probe the real-time dynamics of all phonon modes of a material. Read More »

Synopsis: Magnetic Cloak Without Superconductors
Magnetism

Synopsis: Magnetic Cloak Without Superconductors

A new magnetic-cloak device works without requiring cryogenically cooled superconductors. Read More »

More Articles