Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New material provides a key to explaining superconductivity

20.10.2009
Superconductors are materials that conduct electricity with almost no resistance, and engineers are simply crazy about them.

Physicists around the world are working hard to explain this physical phenomenon. Yet, to this day, nobody knows exactly why some materials suddenly become superconductors below a certain temperature. Researchers at Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) present new findings in the current issue of Nature Materials that could finally resolve a long-standing dispute as to which theory is correct.

One thing is for sure: a phase transition from "non-conducting" to "conducting" occurs at around the transition temperature - below which electrical resistance drops to barely measurable. The atoms in the crystalline lattice rearrange themselves, and the material can take on new properties. One theory proposes that superconductivity is a property already inherent in the source materials used to produce superconductors. These source materials are always insulators; that is, materials that do not conduct electricity.

They only become conductive after a process called doping, where foreign atoms are incorporated into the crystalline lattice. The second theory proposes that two phases "compete" as the material approaches the transition temperature, and that superconductivity arises out of this phenomenon. "Our findings confirm the correctness of this [latter] theory", says Dimitri Argyriou of HZB.

He and his team investigated a lanthanum-strontium-manganate compound. This material is not an actual superconductor, but it is similarly produced by doping an insulating material. As it is, however, lanthanum-strontium-manganate is a poor conductor. Argyriou and his team studied this novel metal by neutron scattering and discovered a difference from normal metals.

In pure metals such as copper, there are free electrons that allow the flow of electric current, where present theory has it that these electrons accumulate to form a so-called electron gas.

In lanthanum-strontium-manganate, the HZB researchers have discovered, the free electrons only briefly behave as an electron gas. They do not "forget" that they originated from an insulator and suddenly become trapped again in the crystalline lattice. They actually alternate between these two states, becoming free (conductive) for a time, and then becoming trapped (non-conductive) again.

"This behaviour proves that the insulator property remains anchored in the doped material's memory, and that the property of superconductivity does not exist in the source material", Dimitri Argyriou concludes.

Institute Complex Magnetic Materials
Dr. Dimitri Argyriou
Tel.: (030) 8062-3016
Fax: (030) 8062-2999
Email: argyriou@helmholtz-berlin.de
Press office
Dr. Ina Helms
Tel.: (030) 8062-2034
Fax: (030) 8062-2998
Email: ina.helms@helmholtz-berlin.de

Dr. Ina Helms | idw
Further information:
http://www.helmholtz-berlin.de

Further reports about: HZB Superconductivity crystalline lattice electron gas

More articles from Materials Sciences:

nachricht Strange but true: Turning a material upside down can sometimes make it softer
20.10.2017 | Universitat Autonoma de Barcelona

nachricht Metallic nanoparticles will help to determine the percentage of volatile compounds
20.10.2017 | Lomonosov Moscow State University

All articles from Materials Sciences >>>

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

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>