Their work, published in Physical Review Letters, examines the role of chemical dopants, which are essential to creating high-temperature superconductors – materials that conduct electricity without resistance.
Minghu Pan's image of "clover-like" atomic defects — an example is circled — that result in strong superconductivity.
The role of dopants in superconductors is particularly mysterious as they introduce non-uniformity and disorder into the crystal structure, which increases resistivity in non-superconducting materials.
By gaining a better understanding of how and why chemical dopants alter the behavior of the original (parent) material, scientists believe they can design superconductors that work at higher temperatures. This would make them more practical for real-world wire applications because it would lessen the extreme cooling required for conventional superconducting material. Existing "high-temperature superconductors” operate at temperatures in the range of negative 135 degrees Celsius and below.
“Through this work, we have created a framework that allows us to understand the interplay of superconductivity and inhomogeneity,” said lead author Krzysztof Gofryk, a post-doctoral fellow in the Department of Energy laboratory’s Materials Science and Technology Division. “Thus, for the first time we have a clearer picture of the side effects of dopants.”
ORNL’s Athena Safa-Sefat, who led the team, noted that while scientists have made progress since the first observation of superconductivity in the Dutch province of South Holland in 1911, they still do not know what causes some complex multicomponent materials to be superconductive at high temperatures. Additional progress will most likely hinge on answering fundamental questions regarding the interactions of atoms with the crystal, and this work represents a step forward.
“Our bulk and atomic-scale measurements on an iron-based superconductor have revealed that strong superconductivity comes from highly doped regions in the crystal where dopants are clustered,” Sefat said. “If we can design a crystal where such clusters join in an organized manner, we can potentially produce a much higher performance superconductor.”
While several companies manufacture superconducting materials that have been used in specialty applications and demonstration settings, widespread adoption is restricted by cost and complexity. An ideal superconducting wire would be constructed from inexpensive, earth-abundant non-toxic elements. It will also be low-cost for the manufacture of long lengths that are round and flexible and feature good mechanical – non-brittle – properties with a high superconducting temperature.
Other authors of the paper, titled “Local inhomogeneity and filamentary superconductivity in Pr-doped CaFe2As2,” are Minghu Pan, Claudia Cantoni, Bayrammurad Saparov and Jonathan Mitchell. This research was funded by DOE’s Office of Science.
UT-Battelle manages ORNL for the Department of Energy’s Office of Science. DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of the time. For more information, please visit science.energy.gov.
Ron Walli | EurekAlert!
Winds a quarter the speed of light spotted leaving mysterious binary systems
29.04.2016 | University of Cambridge
Possible Extragalactic Source of High-Energy Neutrinos
28.04.2016 | Julius-Maximilians-Universität Würzburg
Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.
Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...
Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.
In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...
Honeycomb structures as the basic building block for industrial applications presented using holo pyramid
Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...
Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences (CAS). This work is about avoiding costly and unstable fullerenes.
Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences...
As one of the leading R&D partners in the development of surface technologies and organic electronics, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP will be exhibiting its recent achievements in vacuum coating of ultra-thin glass at SVC TechCon 2016 (Booth 846), taking place in Indianapolis / USA from May 9 – 13.
Fraunhofer FEP is an experienced partner for technological developments, known for testing the limits of new materials and for optimization of those materials...
27.04.2016 | Event News
15.04.2016 | Event News
12.04.2016 | Event News
29.04.2016 | Physics and Astronomy
29.04.2016 | Health and Medicine
29.04.2016 | Life Sciences