Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Channelling waste heat in microprocessors in new directions

27.07.2011
What happens when you heat up a magnet? When a material is heated, the temperature differential in the electrons generates an electrical voltage known as thermopower or the Seebeck effect.

An international team of researchers at the Universities of Göttingen, Bielefeld and Giessen, along with the Massachusetts Institute of Technology (MIT) in the USA, has now developed a new method that influences the electron’s thermopower in the tunnel junction by directly changing magnetisation. This way, they can control the conversion of heat into electrical energy. The results may contribute to the future development of novel, economical microprocessors.


Schematic diagram of how thermopower in the magnetic tunnel junction is switched via antiparallel (AP) or parallel (P) magnetisation.
Göttingen University

DFG funds additional collaborative research to the tune of one million euros

Spin caloritronics is a new area of research: What happens when you heat up a magnet? When a material is heated, the temperature differential in the electrons generates an electrical voltage known as thermopower or the Seebeck effect. Electronic components made of magnetic materials – consisting of two magnetic layers separated by a thin oxide film only a few atomic layers thick – for example, are used as reading heads for hard drives. Current research focuses on the use of such magnetic tunnel junctions as nonvolatile memory elements in processors where data are preserved without an energy supply. An international team of researchers at the Universities of Göttingen, Bielefeld and Giessen, along with the Massachusetts Institute of Technology (MIT) in the USA, has now developed a new method that influences the electron’s thermopower in the tunnel junction by directly changing magnetisation. This way, they can control the conversion of heat into electrical energy. The results may contribute to the future development of novel, economical microprocessors and were published on Sunday, July 24, 2011 in the online issue of “Nature Materials“.

Elementary particles, many atomic nuclei and atoms with certain electron configurations have what is called spin – defined as the rotation of a body around its own axis. That enables alternative, spin-based methods of electronic data processing – called “spin electronics“. New synergies are created by merging the fields of spin electronics and the energy conversion of novel materials. A Japanese team of researchers recently showed that tunnel barriers enable thermal spin injection into the semiconductor silicon.

The team of researchers around the Göttingen physicist Professor Markus Münzenberg has now used laser power to heat up magnetic tunnel junctions and thereby discovered a novel effect: Thermopower was created during spin transport through the thin oxide layer (tunnel barrier) the heated up electrons traverse. They could raise or lower the thermopower by changing the magnetisation. In doing so, they influenced the thermopower of the whole magnetic tunnel junction. They predict that a change in thermopower of up to 1000 % is possible. This newly discovered effect involving the switching of thermopower in magnetic tunnel junctions was dubbed the magneto-Seebeck effect. “This has released the potential for us to locally control energy conversion in the tiniest of junctions and, in the future, for example, to channel back into the computer system the energy generated in microprocessors that previously went unutilised, or computer chips working with waste heat only” said Prof. Münzenberg, who leads a research group at the 1st Institute of Physics of Göttingen University. Since July 2011, the collaborative research of these working groups at the three German universities has been part of the priority programme titled “Spin Caloric Transport (SpinCat) – SPP 1538“, funded by the German Research Foundation (DFG) to the tune of over one million euros.

Original publication:
M. Walter, J. Walowski, V. Zbarsky, M. Münzenberg et al, Seebeck effect in magnetic tunnel junctions, Nature Materials, published online 24 July 2011, DOI: 10.1038/NMAT3076
Contact address:
Professor Markus Münzenberg
Georg-August University Göttingen
Faculty of Physics – Physical Institute I
Friedrich-Hund-Platz 1, 37077 Göttingen
Phone (0551) 39-7604, Fax (0551) 39-12229
E-mail: mmuenze@gwdg.de

Dr. Bernd Ebeling | Uni Göttingen
Further information:
http://www.uni-goettingen.de/de/99100.html

More articles from Power and Electrical Engineering:

nachricht Waste from paper and pulp industry supplies raw material for development of new redox flow batteries
12.10.2017 | Johannes Gutenberg-Universität Mainz

nachricht Low-cost battery from waste graphite
11.10.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>