q&more
My watch list
my.chemie.de  
Login  

News

Crystal structures in super slow motion

Researchers first to succeed in filming a phase transition with extremely high spatial and temporal resolution

Dr Murat Sivis

At the heart of the imaging technique is a complex array of 72 circular apertures

Dr Florian Sterl (Sterltech Optics)

Artist's impression of the charge density wave in the ultrafast transmission electron microscope.

26-Jan-2021: Laser beams can be used to change the properties of materials in an extremely precise way. This principle is already widely used in technologies such as rewritable DVDs. However, the underlying processes generally take place at such unimaginably fast speeds and at such a small scale that they have so far eluded direct observation. Researchers at the University of Göttingen and the Max Planck Institute (MPI) for Biophysical Chemistry in Göttingen have now managed to film, for the first time, the laser transformation of a crystal structure with nanometre resolution and in slow motion in an electron microscope.

The team, which includes Thomas Danz and Professor Claus Ropers, took advantage of an unusual property of a material made up of atomically thin layers of sulphur and tantalum atoms. At room temperature, its crystal structure is distorted into tiny wavelike structures - a "charge-density wave" is formed. At higher temperatures, a phase transition occurs in which the original microscopic waves suddenly disappear. The electrical conductivity also changes drastically, an interesting effect for nano-electronics.

In their experiments, the researchers induced this phase transition with short laser pulses and recorded a film of the charge-density wave reaction. "What we observe is the rapid formation and growth of tiny regions where the material was switched to the next phase," explains first author Thomas Danz from Göttingen University. "The Ultrafast Transmission Electron Microscope developed in Göttingen offers the highest time resolution for such imaging in the world today." The special feature of the experiment lies in a newly developed imaging technique, which is particularly sensitive to the specific changes observed in this phase transition. The Göttingen physicists use it to take images that are composed exclusively of electrons that have been scattered by the crystal's waviness.

Their cutting-edge approach allows the researchers to gain fundamental insights into light-induced structural changes. "We are already in a position to transfer our imaging technique to other crystal structures," says Professor Claus Ropers, leader of Nano-Optics and Ultrafast Dynamics at Göttingen University and Director at the MPI for Biophysical Chemistry. "In this way, we not only answer fundamental questions in solid-state physics, but also open up new perspectives for optically switchable materials in future, intelligent nano-electronics."

Original publication:
Thomas Danz et al.; "Ultrafast nanoimaging of the order parameter in a structural phase transition"; Science; 2021

Facts, background information, dossiers

  • crystal structures
  • phase transitions
  • nanoelectronics

More about Uni Göttingen

  • News

    How the cell protects itself

    The cell contains transcripts of the genetic material, which migrate from the cell nucleus to another part of the cell. This movement protects the genetic transcripts from the recruitment of “spliceosomes”. If this protection does not happen, the entire cell is in danger: meaning that cance ... more

    Stickier than expected: Hydrogen binds to graphene in 10 femtoseconds

    Graphene is celebrated as an extraordinary material. It consists of pure carbon, only a single atomic layer thick. Nevertheless, it is extremely stable, strong, and even conductive. For electronics, however, graphene still has crucial disadvantages. It cannot be used as a semiconductor, sin ... more

    Researchers combine light and X-ray microscopy for comprehensive insights

    Researchers at the University of Goettingen have used a novel microscopy method. In doing so they were able to show both the illuminated and the "dark side" of the cell. The team led by Prof. Dr. Tim Salditt and Prof. Dr. Sarah Köster from the Institute of X-Ray Physics "attached" small fl ... more

More about MPI für biophysikalische Chemie

  • News

    World record resolution in cryo-electron microscopy

    A crucial resolution barrier in cryo-electron microscopy has been broken. Holger Stark and his team at the Max Planck Institute (MPI) for Biophysical Chemistry have observed single atoms in a protein structure for the first time and taken the sharpest images ever with this method. Such unpr ... more

    Virus multiplication in 3D

    Vaccinia viruses serve as a vaccine against human smallpox and as the basis of new cancer therapies. Two studies now provide fascinating insights into their unusual propagation strategy at the atomic level. For viruses to multiply, they usually need the support of the cells they infect. In ... more

    Stickier than expected: Hydrogen binds to graphene in 10 femtoseconds

    Graphene is celebrated as an extraordinary material. It consists of pure carbon, only a single atomic layer thick. Nevertheless, it is extremely stable, strong, and even conductive. For electronics, however, graphene still has crucial disadvantages. It cannot be used as a semiconductor, sin ... more

q&more – the networking platform for quality excellence in lab and process

The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.

> more about q&more

q&more is supported by:

 

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE