Featured Research

from universities, journals, and other organizations

Electron microscopes with a twist: Vortex beams, rotating like a tornado, offer new possibilities for electron microscopy

Date:
November 5, 2012
Source:
Vienna University of Technology, TU Vienna
Summary:
Vortex beams, rotating like a tornado, offer completely new possibilities for electron microscopy.  A method of producing extremely intense vortex beams has been discovered.

The electron beam passes through a screen and is transformed into a vortex beam.
Credit: Image courtesy of Vienna University of Technology, TU Vienna

Vortex beams, rotating like a tornado, offer completely new possibilities for electron microscopy. A method of producing extremely intense vortex beams has been discovered at the Vienna University of Technology (TU Vienna).

Nowadays, electron microscopes are an essential tool, especially in the field of materials science. At TU Vienna, electron beams are being created that possess an inner rotation, similarly to a tornado. These "vortex beams" cannot only be used to display objects, but to investigate material-specific properties -- with precision on a nanometer scale. A new breakthrough in research now allows scientists to produce much more intense vortex beams than ever before.

Quantum Tornado: the Electron as a Wave

In a tornado, the individual air particles do not necessarily rotate on their own axis, but the air suction overall creates a powerful rotation. The rotating electron beams that have been generated at TU Vienna behave in a very similar manner. In order to understand them, we should not think of electrons simply as minuscule points or pellets, as in that case they could at most rotate on their own axis. Vortex beams, on the other hand, can only be explained in terms of quantum physics: the electrons behave like a wave, and this quantum wave can rotate like a tornado or a water current behind a ship's propeller.

"After the vortex beam gains angular momentum, it can also transfer this angular momentum to the object that it encounters," explained Prof. Peter Schattschneider from the Institute of Solid State Physics at TU Vienna. The angular momentum of the electrons in a solid object is closely linked to its magnetic properties. For materials science it is therefore a huge advantage to be able to make statements regarding angular momentum conditions based on these new electron beams.

Beams Rotate -- With Masks and Screens

Peter Schattschneider and Michael Stφger-Pollach (USTEM, TU Vienna) have been working together with a research group from Antwerp on creating the most intense, clean and controllable vortex beams possible in a transmission electron microscope. The first successes were achieved two years ago: at the time, the electron beam was shot through a minuscule grid mask, whereby it split into three partial beams: one turning right, one turning left and one beam that did not rotate.

Now, a new, much more powerful method has been developed: researchers use a screen, half of which is covered by a layer of silicon nitride. This layer is so thin that the electrons can penetrate it with hardly any absorption, however they can be suitably phase-shifted. "After focusing using a specially adapted astigmatic lens, an individual vortex beam is obtained," explained Michael Stφger-Pollach.

This beam is more intense by one order of magnitude than the vortex beams that we have been able to create to date. "Firstly, we do not split the beam into three parts, as is the case with a grid mask, but rather, the entire electron stream is set into rotation. Secondly, the grid mask had the disadvantage of blocking half of the electrons -- the new special screen does not do this," said Stφger-Pollach.

Thanks to the new technology, right and left-rotating beams can now be distinguished in a reliable manner -- previously this was only possible with difficulty. If we now add a predetermined angular momentum to each right and left-rotating beam, the rotation of one beam is increased, while the rotation of the other beam decreases.

Electron microscopes with a twist

This new technology was briefly presented by the research team in the "Physical Review Letters" journal. In future, the aim is to apply the method in materials science. Magnetic properties are often the focus of attention, particularly in the case of newly developed designer materials. "A transmission electron microscope with vortex beams would allow us to investigate these properties with nanometric precision," explained Peter Schattschneider.

More exotic applications of vortex beams are also conceivable: in principle, it is possible to set all kinds of objects in rotation -- even individual molecules -- using these beams, which possess angular momentum. Vortex beams could therefore also open new doors in nanotechnology.


Story Source:

The above story is based on materials provided by Vienna University of Technology, TU Vienna. Note: Materials may be edited for content and length.


Cite This Page:

Vienna University of Technology, TU Vienna. "Electron microscopes with a twist: Vortex beams, rotating like a tornado, offer new possibilities for electron microscopy." ScienceDaily. ScienceDaily, 5 November 2012. <www.sciencedaily.com/releases/2012/11/121105100845.htm>.
Vienna University of Technology, TU Vienna. (2012, November 5). Electron microscopes with a twist: Vortex beams, rotating like a tornado, offer new possibilities for electron microscopy. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2012/11/121105100845.htm
Vienna University of Technology, TU Vienna. "Electron microscopes with a twist: Vortex beams, rotating like a tornado, offer new possibilities for electron microscopy." ScienceDaily. www.sciencedaily.com/releases/2012/11/121105100845.htm (accessed October 23, 2014).

Share This



More Matter & Energy News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

3D Printed Instruments Make Sweet Music in Sweden

3D Printed Instruments Make Sweet Music in Sweden

Reuters - Innovations Video Online (Oct. 23, 2014) — Students from Lund University's Malmo Academy of Music are believed to be the world's first band to all use 3D printed instruments. The guitar, bass guitar, keyboard and drums were built by Olaf Diegel, professor of product development, who says 3D printing allows musicians to design an instrument to their exact specifications. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) — Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) — Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Internet of Things Aims to Smarten Your Life

Internet of Things Aims to Smarten Your Life

AP (Oct. 22, 2014) — As more and more Bluetooth-enabled devices are reaching consumers, developers are busy connecting them together as part of the Internet of Things. (Oct. 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins