Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Effect Couples Electricity and Magnetism in Materials

28.11.2013
In magneto-electric materials, electric and magnetic vibrations can be coupled to “electromagnons”. High hopes are placed on this technology, a breakthrough could now be achieved at the Vienna University of Technology (TU Wien).

Major industries such as modern microelectronics are based on the interaction between matter and electromagnetism. Electromagnetic signals can be processed and stored in specially tailored materials.


Prof. Andrei Pimenov in his Lab

In materials science, electric and magnetic effects have usually been studied separately. There are, however, extraordinary materials called “multiferroics”, in which electric and magnetic excitations are closely linked. Scientists at the Vienna University of Technology (TU Wien) have now shown in an experiment that magnetic properties and excitations can be influenced by an electric voltage. This opens up completely new possibilities for electronics at high frequencies.

The Best of Two Worlds

It has been well known for a long time that electricity and magnetism are two sides of the same coin. Waves in free space, such as visible light or mobile phone radiation, always consist of both an electric and a magnetic component. When it comes to material properties, however, electricity and magnetism have been viewed as separate topics. There are materials with magnetic ordering, which react to magnetic fields, and there are materials with electric ordering, which can be influenced by electric fields.

A magnet has a magnetic field, but no electric field. In a piezoelectric crystal, on the other hand, electric fields can be generated, but no magnetic fields. Having both at the same time seemed impossible. “Usually, both effects are created in very different ways”, says Professor Andrei Pimenov (TU Vienna). “Magnetic ordering comes from electrons aligning their magnetic moments, electric ordering comes from positive and negative charges moving with respect to one another.”

Electromagnons

In 2006, Andrei Pimenov (while working at Augsburg University) found evidence of excitations which are based on both electric and magnetic ordering. These excitations, which have been dubbed “electromagnons”, have been hotly debated by materials scientists ever since. Now Pimenov and his team have succeeded in switching such excitations on and off with an electric field in a special material made of dysprosium, manganese and oxygen (DyMnO3).

In this material, many electrons align their magnetic moments at low temperatures. Each electron has a magnetic direction which is slightly distorted with respect to the adjoining electron – therefore the electrons create spiral of magnetic moments. The spiral has two possible orientations – clockwise or counterclockwise – and, surprisingly, an external electric field can switch between these two possibilities.

Vibrating Atoms, Wobbling Moments

In magneto-electric materials, the charges and the magnetic moments of the atoms are connected. In dysprosium manganese oxide, this connection is particularly strong: “When the magnetic moments wobble, the electric charges move too”, says Andrei Pimenov. In this material, magnetic moments and electric charges simultaneously play a part in the excitation, and therefore both can be influenced by one single external field.

The effect can be demonstrated by sending terahertz radiation through the material: The polarization of the terahertz beam is changed if the multiferroic material exhibits magnetic ordering. If the magnetic spiral in the material can be switched with an electric field, this electric field eventually determines, whether the polarization of the terahertz beam is being rotated.

There are many ideas for future applications: Wherever it is desirable to combine the respective advantages of magnetic and electric effects, the new magneto-electric materials could be used in the future. This could lead to new kinds of amplifiers, transistors or data storage devices. Also, highly sensitive sensors could be built with electromagnon technology.

Further Information:
Prof. Andrei Pimenov
Institute of Solid State Physics
Vienna University of Technology
Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria
T: +43-1-58801-137 23
andrei.pimenov(at)tuwien.ac.at

Florian Aigner | EurekAlert!
Further information:
http://www.tuwien.ac.at

More articles from Materials Sciences:

nachricht Pressure tuned magnetism paves the way for novel electronic devices
18.12.2018 | Bar-Ilan University

nachricht Researchers observe charge-stripe crystal phase in an insulating cuprate
18.12.2018 | Boston College

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Pressure tuned magnetism paves the way for novel electronic devices

18.12.2018 | Materials Sciences

New type of low-energy nanolaser that shines in all directions

18.12.2018 | Physics and Astronomy

NASA research reveals Saturn is losing its rings at 'worst-case-scenario' rate

18.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>