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!
Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie
Seeing the quantum future... literally
16.01.2017 | University of Sydney
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Life Sciences
18.01.2017 | Health and Medicine
17.01.2017 | Earth Sciences