The behavior of intermetallic superconductors, like the kind used in hospital MRI machines, is even more curious than recent Nobel Prize-winning physicist Alexei Abrikosov had theorized. In newly reported research,* scientists working at the National Institute of Standards and Technology (NIST) Center for Neutron Research have determined that so-called type II superconductors have the equivalent of a multiple personality---at least three distinct physical states, each with its own superconducting behavior. The result should help engineers design new materials for stronger, more efficient superconducting magnets.
Nearly 50 years ago, Abrikosov predicted that superconductors could retain superconductivity in a very strong magnetic field by forming tiny eddies of current. These vortices allow the field to pass through without disrupting the current, until a certain threshold is reached and the resistance-free flow of electrons ceases. Just before the collapse, however, the materials undergo a dramatic spike in current, called the peak effect.
Over a wide range of temperatures and magnetic field strengths, Brown University and NIST scientists tracked the movements of current eddies in a prototype type II superconductor, niobium. Their experiments yielded a phase diagram, a kind of a map that shows how current vortices rearrange in response to changes in temperature and magnetic field.
Mark Bello | EurekAlert!
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07.08.2017 | University of Manchester
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
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