 |
|
Finding superconductors that can take the heat
November 09, 2005By studying how superconductors interact with magnetic fields, Pitt researchers advance quest for higher-temperature superconducting materials
Superconductors are materials with no electrical resistance that are used to make strong magnets and must be kept extremely cold-otherwise, they lose their superconducting abilities. Even the "high-temperature" superconductors discovered in the 1980s must be kept at around -300°F.
The search for superconductors that function at higher temperatures has taken a step forward with new findings from University of Pittsburgh professor of physics and astronomy Yadin Y. Goldschmidt and former Pitt postdoctoral associate Eduardo Cuansing that were published in the Oct. 21 issue of the journal Physical Review Letters.
When a superconductor is exposed to a magnetic field, the field penetrates it in the form of thin tubes, called vortices. Around each tube circulates an electric current. These vortices arrange themselves into patterns and melt when the temperature of the material is raised.
"This melting transition of the vortices is important, because it usually causes superconductivity to disappear," said Goldschmidt. "It is thus beneficial to delay the full melting as much as possible."
In addition to confirming previous experimental results, Goldschmidt and Cuansing used computer simulations of the vortex melting process to find, for the first time, direct evidence of new vortex patterns.
"Experimentalists can hardly see individual vortices," said Goldschmidt. "But with our simulations, we can actually see a picture of what's going on inside the material."
Since the vortices tend to attach to long, thin holes in the material, called columnar defects, the Pitt researchers suspected that the vortices would behave differently in the presence of such defects. And they did: When there were more vortices than holes, the vortex matter melted in two stages instead of one as the temperature was raised.
"Once physicists understand these melting mechanisms, they may be able to design materials that remain superconductors at higher temperatures," Goldschmidt said.
University of Pittsburgh
When a superconductor is exposed to a magnetic field, the field penetrates it in the form of thin tubes, called vortices. Around each tube circulates an electric current. These vortices arrange themselves into patterns and melt when the temperature of the material is raised.
"This melting transition of the vortices is important, because it usually causes superconductivity to disappear," said Goldschmidt. "It is thus beneficial to delay the full melting as much as possible."
In addition to confirming previous experimental results, Goldschmidt and Cuansing used computer simulations of the vortex melting process to find, for the first time, direct evidence of new vortex patterns.
"Experimentalists can hardly see individual vortices," said Goldschmidt. "But with our simulations, we can actually see a picture of what's going on inside the material."
Since the vortices tend to attach to long, thin holes in the material, called columnar defects, the Pitt researchers suspected that the vortices would behave differently in the presence of such defects. And they did: When there were more vortices than holes, the vortex matter melted in two stages instead of one as the temperature was raised.
"Once physicists understand these melting mechanisms, they may be able to design materials that remain superconductors at higher temperatures," Goldschmidt said.
University of Pittsburgh
Superconductors Current Events and Superconductors News RSSNew study confirms exotic electric properties of graphene
First, it was the soccer-ball-shaped molecules dubbed buckyballs. Then it was the cylindrically shaped nanotubes. Now, the hottest new material in physics and nanotechnology is graphene: a remarkably flat molecule made of carbon atoms arranged in hexagonal rings much like molecular chicken wire.
Quantum gas microscope offers glimpse of quirky ultracold atoms
Physicists at Harvard University have created a quantum gas microscope that can be used to observe single atoms at temperatures so low the particles follow the rules of quantum mechanics, behaving in bizarre ways.
Putting a Strain on Nanowires Could Yield Colossal Results
In finally answering an elusive scientific question, researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have shown that the selective placement of strain can alter the electronic phase and its spatial arrangement in correlated electron materials.
Atoms don't dance the 'bose nova'
Hanns-Christoph Naegerl's research group has investigated how ultracold quantum gases behave in lower spatial dimensions. They successfully realized an exotic state, where, due to the laws of quantum mechanics, atoms align along a one-dimensional structure.
Scientists detect 'fingerprint' of high-temp superconductivity above transition temperature
A team of U.S. and Japanese scientists has shown for the first time that the spectroscopic "fingerprint" of high-temperature superconductivity remains intact well above the super chilly temperatures at which these materials carry current with no resistance.
Superconductivity: Which one of these is not like the other?
Superconductivity appears to rely on very different mechanisms in two varieties of iron-based superconductors.
Discovery at UAB brings us nearer to making the dream of invisibility true
A group of researchers from the Department of Physics at UAB have designed a device, called a dc metamaterial, which makes objects invisible under certain light - very low frequency electromagnetic waves - by making the inside of the magnetic field zero but not altering the exterior field.
NIST discovers how strain at grain boundaries suppresses high-temperature superconductivity
Researchers at the National Institute of Standards and Technology (NIST) have discovered that a reduction in mechanical strain at the boundaries of crystal grains can significantly improve the performance of high-temperature superconductors (HTS).
New Exotic Material Could Revolutionize Electronics
Move over, silicon-it may be time to give the Valley a new name. Physicists at the Department of Energy's (DOE) SLAC National Accelerator Laboratory and Stanford University have confirmed the existence of a type of material that could one day provide dramatically faster, more efficient computer chips.
Thinnest superconducting metal created
A superconducting sheet of lead only two atoms thick, the thinnest superconducting metal layer ever created, has been developed by physicists at The University of Texas at Austin.
More Superconductors Current Events and Superconductors News Articles
 |
Economy Superconductivity Kit by Arbor Scientific Our superconductivity kit features a large superconductive disc formulated from the oxides of Yttrium, Barium, and Copper in the famous 1-2-3 chemical combination. The disc has a critical temperature of 92 degrees Kelvin. Chill the disc to 77 degrees Kelvin with liquid nitrogen and it produces a striking Meissner Effect (magnetic levitation) when the neodymium magnet is introduced. Kit Includes: One Super Conductive Disc (1" dia. x 1/8") One Neodymium Magnet (1/8" dia. x 1/8") One Petri Dish Cover Low Temperature Plastic Forceps Instructions & Safety Precautions |
 |
Introduction to Superconductivity: Second Edition (Dover Books on Physics) (Vol i) by Michael Tinkham (Author) Accessible to graduate students and experimental physicists, this volume emphasizes physical arguments and minimizes theoretical formalism. Topics include the Bardeen-Cooper-Schrieffer and Ginzburg-Landau theories, magnetic properties of classic type II superconductors, the Josephson effect, fluctuation effects in classic superconductors, high-temperature superconductors, and nonequilibrium superconductivity. 109 figures. 1996 edition. |
 |
Hit Songs for Girls by Superconductor |
 |
Voltage Superconductor by Voltage Security, Inc. If you are interested in the underpinnings of enterprise security, cryptography or how security and usability are intimately connected - this blog will make you happyKindle blogs are fully downloaded onto your Kindle so you can read them even when you're not wirelessly connected. And unlike RSS readers which often only provide headlines, blogs on Kindle give you full text content and images, and are updated wirelessly throughout the day. |
 |
Hit Songs for Girls Superconductor (Primary Contributor) |
|
|
Complete Superconductivity Kit by Arbor Scientific Our superconductivity kit features a large superconductive disc formulated from the oxides of Yttrium, Barium, and Copper in the famous 1-2-3 chemical combination. The disc has a critical temperature of 92 degrees Kelvin. Chill the disc to 77 degrees Kelvin with liquid nitrogen and it produces a striking Meissner Effect (magnetic levitation) when the neodymium magnet is introduced. Kit Includes: One Super Conductive Disc (1" dia. x 1/8") One Neodymium Magnet (1/8" dia. x 1/8") One Petri Dish Cover Low Temperature Plastic Forceps One Thermos container, Gloves & Goggles Instructions & Safety Precautions |
 |
Avanti White Compact SUPERCONDUCTOR Refrigerator by Avanti Avanti White Compact SUPERCONDUCTOR Refrigerator - SHP1700WH. 1.7 Cu. Ft. Capacity. Thermoelectric Technology. Full Range Temperature Control. Slide-Out Shelf. Environmentally Friendly. Reversible Door. White Finish |
 |
Avanti Superconductor Refrigerator - Black (1.7 cu. ft.) by Avanti Features. 1.7 CU. FT. CAPACITY. High Efficiency. Solid State Components of Superior Reliability. No Vibration. Unique State-of-the-Art Thermoelectric Technology. Environmentally Friendly. Full Range Temperature Control. Reversible Door - Left or Right Swing. Soft Interior Light with ON/OFF Switch. Slide-Out Shelf. Tall Bottle Rack - Holds 2 Liter Bottle. |
|
SciEd Basic Superconductivity Levitation Kit; Complete Demonstration Kit by Colorado Superconductor Kit, Basic Superconductivity Levitation, demonstrates Meissner Effect and Low Friction Magnetic Bearings | |
|
Chemistry of High-Temperature Superconductors (Acs Symposium Series) (Vol 1) by David L. Nelson (Author), M. Stanley M. Whittingham (Author), Thomas F. George (Editor) |
| © 2009 BrightSurf.com |