Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Research on "Holes" May Unearth Causes of Superconductivity

28.10.2004


Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have uncovered another possible clue to the causes of high-temperature superconductivity, a phenomenon in which the electrical resistance of a material disappears below a certain temperature. In a superconducting compound, they found evidence of a rarely seen arrangement of “holes” – locations where electrons are absent. The results appear in the October 28, 2004, issue of Nature.



The researchers were studying a compound made of strontium, copper, and oxygen (which they’ve dubbed SCO) that is one of the “cuprates,” a family of compounds that contain copper oxide. In SCO, the scientists found evidence of a “hole crystal” – a rigid, ordered arrangement of holes. Holes are positively charged and, like electrons, may interact with each other to produce a superconducting current. “A hole crystal is a very unusual phenomenon,” said Brookhaven physicist Peter Abbamonte, the study’s lead researcher. “Its existence is a direct result of the correlations between holes, which are believed to produce superconductivity in other cuprates.”

SCO consists of one layer of strontium atoms sandwiched by two sheets of different copper oxides. In one sheet, the copper-oxide molecules form long, parallel chains. The other copper-oxide layer, which contains the hole crystal, has a ladder structure, resembling chains that are linked horizontally. A hole crystal is just one type of arrangement of electric charge in a material. These arrangements are important because some researchers believe that superconductivity is the result of a particular arrangement, or occurs when a superconductor approaches a boundary between two arrangements. In other cuprates, for example, scientists are studying a charge arrangement in which ribbons of holes and magnetic regions form alternating “stripes.” “We believe the hole crystal and stripes may be linked,” said Abbamonte. “Specifically, the hole crystal in SCO may be a ‘low-dimensional’ precursor to stripes, meaning it exists only along the copper-oxide ladders, rather than in an entire copper-oxide plane.”


He and his collaborators studied SCO using x-rays from the National Synchrotron Light Source, a facility at Brookhaven Lab that produces x-ray, ultraviolet, and infrared light for research in a variety of scientific fields. They placed an SCO sample in the path of an x-ray beam, varied the wavelength of the beam, and watched how the x-rays reflected away from the sample.

At a particular energy, the sample reflected back the x-rays very intensely. The research group discovered that this reflection was caused by the holes, which led them to determine that the holes formed an ordered lattice since randomly placed holes could not have produced such a strong reflection.

Abbamonte and his collaborators plan to continue this research by varying the chemical composition of SCO to see if it changes the hole crystal. They will also examine another cuprate to see if its stripes are related to the crystal. “Clearly, more research needs to be done to study these phases and their possible link to superconductivity,” said Abbamonte.

The research was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy’s Office of Science, the National Science Foundation, Bell Laboratories, the Dutch Science Foundation, and the Netherlands Organization for Fundamental Research on Matter.

Laura Mgrdichian | EurekAlert!
Further information:
http://www.bnl.gov

More articles from Power and Electrical Engineering:

nachricht Positrons as a new tool for lithium ion battery research: Holes in the electrode
22.02.2017 | Technische Universität München

nachricht Multicrystalline Silicon Solar Cell with 21.9 % Efficiency: Fraunhofer ISE Again Holds World Record
20.02.2017 | Fraunhofer-Institut für Solare Energiesysteme ISE

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Positrons as a new tool for lithium ion battery research: Holes in the electrode

22.02.2017 | Power and Electrical Engineering

New insights into the information processing of motor neurons

22.02.2017 | Life Sciences

Healthy Hiking in Smart Socks

22.02.2017 | Innovative Products

VideoLinks
B2B-VideoLinks
More VideoLinks >>>