Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mercury rising

18.04.2011
Mercury-containing oxides offer a new perspective on the mechanism of superconductivity

To diversify the applications of superconductors that currently operate at chilly temperatures below 135 kelvin (K), scientists are searching for new classes of superconducting materials that will show this property at warmer temperatures.

Now, a research team in Japan has synthesized a promising new class of superconductors[1], made of Hg0.44ReO3, where an unusual motion of the mercury (Hg) atoms enhances superconducting properties at temperatures up to 7.7 K.

The Dutch physicist Heike Kamerlingh Onnes discovered superconductivity one hundred years ago, when he noticed that the electrical resistance of mercury dropped to zero suddenly at 4.2 K. Superconducting materials are now used routinely in magnetic resonance imaging scanners.

In classical superconductors such as mercury, superconductivity arises through the combined vibrations of the atoms in the crystal. This makes the crystal structure a key factor for the superconducting properties of a material. In the case of HgxReO3, the atomic structure consists of rhenium (Re) and oxygen (O) building blocks. In the empty spaces between them, the mercury atoms arrange in chains (Fig. 1). However, some of the available places along these chains lack mercury atoms, and the team’s work suggests that this leads to an arrangement of paired mercury atoms.

"These pairs move within the channel in an oscillatory motion known as rattling", explains team-member Ayako Yamamoto from the RIKEN Advanced Science Institute in Wako. The rattling vibrations provide a strong feedback for the electrons, and therefore reinforce superconductivity in the material. In comparison to a similar structure lacking mercury pairs, the superconducting temperature of Hg0.44ReO3 at 7.7 K is almost twice as high. "Despite remaining below the present record of 135 K for a superconductor, there is potential for improving operation temperatures", says Yamamoto. “The application of pressure increases the superconducting temperature to 11.1 K, and this could mean that for the right crystal structure further enhancement is possible.”

Yamamoto and her colleagues are now working to optimize the crystal structure further—for example, by replacing rhenium with other elements. A better understanding of the influence of the mercury atoms’ rattling motion may also provide better insight into the mechanism of superconductivity in such structures. “Mercury seems to be a magic element in superconductivity, not only for its role in Kamerlingh Onnes’ discovery, but also for the fact that mercury is part of the material with the highest known superconducting temperature, HgBa2Ca2Cu3Ox,” Yamamoto explains. "Once more, mercury is playing a key role for new superconductors," she says.

The corresponding author for this highlight is based at the Magnetic Materials Laboratory, RIKEN Advanced Science Institute

Journal information

[1] Ohgushi, K., Yamamoto, A., Kiuchi, Y., Ganguli, C., Matsubayashi, K., Uwatoko, Y. & Takagi, H. Superconducting phase at 7.7 K in the HgxReO3 compound with a hexagonal bronze structure. Physical Review Letters 106, 017001 (2011).

gro-pr | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6569
http://www.researchsea.com

More articles from Physics and Astronomy:

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

nachricht Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NASA's AIM observes early noctilucent ice clouds over Antarctica

05.12.2016 | Earth Sciences

Shape matters when light meets atom

05.12.2016 | Physics and Astronomy

Researchers uncover protein-based “cancer signature”

05.12.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>