Subscribe free to our newsletters via your
. 24/7 Space News .




ENERGY TECH
Silver Sheds Light On Superconductor Secrets
by Staff Writers
Heidelberg, Germany (SPX) Dec 24, 2012


File image.

The first report on the chemical substitution, or doping, using silver atoms, for a new class of superconductor that was only discovered this year, is about to be published in EPJ B. Chinese scientists from Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, discovered that the superconductivity is intrinsic rather than created by impurities in this material with a sandwich-style layered structure made of bismuth oxysulphide (Bi4O4S3).

Superconductors with a transition temperature (TC) above the boiling temperature of liquid nitrogen (77 kelvins or -196C) are called high TC superconductors. In the quest for such materials, compounds with bismuth disulphide (BiS2) layers have recently started to attract a lot of attention. Indeed, in July 2012, Japanese scientists reported achieving a TC at around 4.5 kelvins (-268.65C) with the first bismuth oxysulphide superconductor.

All the superconducting samples for this new superconductor reported so far are a mixture of Bi4O4S3 and impurities. However, the pure sample without impurities is not superconducting.

Scientists have therefore been wondering whether the observed superconductivity stems from the presence of impurities.The Hefei team performed systematic measurement of the material's characteristics relying on x-ray diffraction, magnetic susceptibility, electrical transport and thermal transport.

Using comparison of the x-ray diffraction patterns, they found that silver atoms partially replace the bismuth sites in the bismuth oxysulphide lattice.

Further experiments involved controlling the composition of the material through various levels of silver doping. The superconductivity, the authors found, was suppressed as the silver content increases and eventually disappears above a certain doping threshold.

They believe that it is the modification of electronic structure upon doping that suppresses the superconductivity.Based on these observations, they concluded that the observed superconductivity originates from the bismuth oxysulphide lattice rather than any impurities.

Reference: 1. S. G. Tan, P. Tong, Y. Liu, W. J. Lu, L. J. Li, B. C. Zhao, Y. P. Sun (2012), Suppression of superconductivity in layered Bi4O4S3 by Ag doping, European Physical Journal B, DOI: 10.1140/epjb/e2012-30975-2

.


Related Links
Springer Select
Powering The World in the 21st Century at Energy-Daily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








ENERGY TECH
Engineers roll up their sleeves - and then do same with inductors
Champaign IL (SPX) Dec 20, 2012
On the road to smaller, high-performance electronics, University of Illinois researchers have smoothed one speed bump by shrinking a key, yet notoriously large element of integrated circuits. Three-dimensional rolled-up inductors have a footprint more than 100 times smaller without sacrificing performance. The researchers published their new design paradigm in the journal Nano Letters. "It ... read more


ENERGY TECH
GRAIL Lunar Impact Site Named for Astronaut Sally Ride

NASA probes crash into the moon

No plans of sending an Indian on moon

Rocket Burn Sets Stage for Dynamic Moon Duos' Lunar Impact

ENERGY TECH
Clays on Mars: More Plentiful Than Expected

Opportunity For Some Shoulder Workout At Copper Cliff

Enabling ChemCam to Measure Key Isotopic Ratios on Mars and Other Planets

Curiosity Rover Explores 'Yellowknife Bay'

ENERGY TECH
NASA Puts Orion Backup Parachutes to the Test

White House to honor scientists, inventors

TDRS-K Arrives at Kennedy for Launch Processing

Sierra Nevada Corporation Selected by NASA to Receive Human Spaceflight Certification Products Contract

ENERGY TECH
Mr Xi in Space

China plans manned space launch in 2013: state media

China to launch manned spacecraft

Tiangong 1 Parked And Waiting As Shenzhou 10 Mission Prep Continues

ENERGY TECH
Expedition 34 Spends Christmas in Space

Three astronauts blast off for ISS in Russian craft

Soyuz rocket brings trio to space station

ISS Orbit Raised Ahead of Crew Arrival

ENERGY TECH
Ariane 5 ECA orbits Skynet 5D and Mexsat Bicentenario satellites

Payload integration complete for final 2012 Ariane 5 mission

Arctic town eyes future as Europe's gateway to space

ISRO planning 10 space missions in 2013

ENERGY TECH
Closest sun-like star may have planets

Nearby star is good candidate for Earth-like planets

Venus transit and lunar mirror could help astronomers find worlds around other stars

Astronomers discover and 'weigh' infant solar system

ENERGY TECH
Berkeley Lab Scientists Developing Quick Way to ID People Exposed to Ionizing Radiation

All Systems Go for Highest Altitude Supercomputer

Space Fence program moving forward

Aldrich Materials Science discovers liquid-free preparation of metal organic frameworks




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement