Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Many Roads lead to Superconductivity

10.09.2010
HZB-Scientists discovered a unique feature of Superconductivity

Since their discovery in 2008, a new class of superconductors has precipitated a flood of research the world over. Unlike the previously familiar copper ceramics (cuprates), the basic structure of this new class consists of iron compounds. Because the structure of these compounds differs from the cuprates in many fundamental ways, there is hope of gaining new insights into how the phenomenon of superconductivity arises.

In cooperation with an international research group, researchers from Helmholtz-Zentrum Berlin (HZB) have now discovered a magnetic signature that occurs universally among all iron-based superconductors, even if the parent compounds from which the superconductors are made possess different chemical properties. Their findings are published in Nature Materials (DOI: 10.1038/NMAT280).

Superconductors are generally produced by “doping” so-called parent compounds, which means introducing foreign atoms into them. There is a strong correlation between magnetism and superconductivity here – both being properties of solids. Conventional superconductors, such as those used in MRI machines in hospitals, do not like magnetism because it disturbs the interactions that lead to superconductivity within the crystal.

It is quite a different story for the celebrated high-temperature superconductors, such as cuprates and iron-arsenic compounds. In these cases, the magnetic forces actually help, even promote the onset of superconductivity. These compounds feature magnetic orders which, if they occur in a crystalline structure, are a telltale sign that the material is suitable to be a high-temperature superconductor.

With the new iron-based superconductors, it turns out that the symmetry of a magnetic order corresponds exactly to the symmetry in the superconductivity signal.

Dimitri Argyriou (HZB) and his colleagues have produced iron-tellurium-selenium crystals and determined their chemical composition using X-ray and neutron diffraction. They measured the magnetic signals in the crystals by performing neutron scattering experiments on the research reactor BER II of HZB and on the research reactor of the Institute Laue-Langevin in Grenoble.

They discovered that the symmetry of the magnetic order is significantly different from that of other iron-based parent compounds, such as iron-arsenic compounds. Yet, surprisingly, this difference has no impact on the development of superconductivity as a property. It has been detected that the magnetic signal caused by superconductivity - often referred to as the magnetic resonance - has the same symmetry as that of the magnetic order. And this is the same in all iron compounds, and apparently follows a universal mechanism that causes superconductivity for all of these materials.

Dimitri Argyriou describes this property as follows: “Going by what we know about the magnetic order of iron compounds, the iron-tellurium-selenium materials ought not to exhibit any superconductivity. But the opposite is the case: Despite the differences in magnetism, the signature of their superconductivity is the same. If we were now to understand how superconductivity arises in light of different starting conditions, then we could perhaps develop materials that are superconductive at even higher temperatures.”

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

More articles from Materials Sciences:

nachricht An innovative high-performance material: biofibers made from green lacewing silk
20.01.2017 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

nachricht Treated carbon pulls radioactive elements from water
20.01.2017 | Rice 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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>