News tagged with superconductors
Unusual 'collapsing' iron superconductor sets record for its class
(PhysOrg.com) -- A team from the National Institute of Standards and Technology and the University of Maryland has found an iron-based superconductor that operates at the highest known temperature for a material ...
Feb 08, 2012 |
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World's longest superconductor cable
The "AmpaCity" project has been kicked off: The RWE Group and its partners are just about to replace a 1-kilometre-long high-voltage cable connecting two transformer stations in the Ruhr city of Essen with ...
Jan 19, 2012 |
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Electron's negativity cut in half by supercomputer
(PhysOrg.com) -- While physicists at the Large Hadron Collider smash together thousands of protons and other particles to see what matter is made of, they're never going to hurl electrons at each other. No ...
Jan 12, 2012 |
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Rice's 'quantum critical' theory gets experimental boost
New evidence this week supports a theory developed five years ago at Rice University to explain the electrical properties of several classes of materials -- including unconventional superconductors -- that ...
Jan 11, 2012 |
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Researchers use webs of lasers to remove entropy from a system causing quantum gases to cool
(PhysOrg.com) -- Many physicists around the world are hard at work trying to figure out new and exciting ways to create ultra-cold objects, the reason being is that if a system could be created that operates ...
Dec 22, 2011 |
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New spectroscopy technique enables investigation of two-dimensional electron states
Understanding and visualizing the energy states of electrons in a crystal provides important insights into many modern electronic materials, such as superconductors, or other materials that physicists can ...
Dec 22, 2011 |
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Chemists propose explanation for superconductivity at high temperatures
(PhysOrg.com) -- It has been 25 years since scientists discovered the first high-temperature superconductors—copper oxides, or cuprates, that conduct electricity without a shred of resistance at temperatures ...
Dec 15, 2011 |
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Graphene earns its stripes: New nanoscale electronic state discovered on graphene sheets
Researchers from the London Centre for Nanotechnology (LCN) have discovered electronic stripes, called 'charge density waves', on the surface of the graphene sheets that make up a graphitic superconductor. ...
Nanotechnology / Nanomaterials
Nov 29, 2011 |
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Emerging new properties at oxide interfaces
In many ionic materials, including the oxides, surfaces created along specific directions can become electrically charged. By the same token, such electronic charging, or 'polarisation', can also occur at the interface of ...
Nov 29, 2011 |
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First proof of single atomic layer material with zero electrical resistance
A research group at the NIMS International Center for Materials Nanoarchitectonics (MANA) has proved that the electrical resistance of a metal single atomic layer on a silicon surface becomes zero by superconductivity.
Nov 24, 2011 |
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Researchers use new approach to overcome key hurdle for next-generation superconductors
Researchers from North Carolina State University have developed a new computational approach to improve the utility of superconductive materials for specific design applications – and have used the approach ...
Oct 27, 2011 |
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Researchers discover material with graphene-like properties
After the Nobel Prize in Physics was awarded to two scientists in 2010 who had studied the material graphene, this substance has received a lot of attention.
Oct 14, 2011 |
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Physicists localize 3-D matter waves for first time (w/ video)
University of Illinois physicists have experimentally demonstrated for the first time how three-dimensional conduction is affected by the defects that plague materials. Understanding these effects is important ...
Oct 07, 2011 |
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Scientists observe how superconducting nanowires lose resistance-free state
Even with today's invisibility cloaks, people can't walk through walls. But, when paired together, millions of electrons can.
Sep 22, 2011 |
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Innovative superconductor fibers carry 40 times more electricity
Wiring systems powered by highly-efficient superconductors have long been a dream of science, but researchers have faced such practical challenges such as finding pliable and cost-effective materials. Now ...
Sep 07, 2011 |
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Superconductivity
Superconductivity is a phenomenon occurring in certain materials generally at very low temperatures, characterized by exactly zero electrical resistance and the exclusion of the interior magnetic field (the Meissner effect). It was discovered by Heike Kamerlingh Onnes in 1911. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It cannot be understood simply as the idealization of "perfect conductivity" in classical physics.
The electrical resistivity of a metallic conductor decreases gradually as the temperature is lowered. However, in ordinary conductors such as copper and silver, impurities and other defects impose a lower limit. Even near absolute zero a real sample of copper shows a non-zero resistance. The resistance of a superconductor, despite these imperfections, drops abruptly to zero when the material is cooled below its "critical temperature". An electric current flowing in a loop of superconducting wire can persist indefinitely with no power source.
Superconductivity occurs in a wide variety of materials, including simple elements like tin and aluminium, various metallic alloys and some heavily-doped semiconductors. Superconductivity does not occur in noble metals like gold and silver, nor in pure samples of ferromagnetic metals.
In 1986 the discovery of a family of cuprate-perovskite ceramic materials known as high-temperature superconductors, with critical temperatures in excess of 90 kelvin, spurred renewed interest and research in superconductivity for several reasons. As a topic of pure research, these materials represented a new phenomenon not explained by the current theory. In addition, because the superconducting state persists up to more manageable temperatures, past the economically-important boiling point of liquid nitrogen (77 kelvin), more commercial applications are feasible, especially if materials with even higher critical temperatures could be discovered.
See also the history of superconductivity.
For more information about Superconductivity, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
