The goal is topological insulators (TI), man-made crystals that are able to conduct electrical current on their surfaces, while acting as insulators throughout the interior of the crystal. Discovering TIs has become of great interest to scientists, but because of the lack of a rational blueprint for creating them, researchers have had to rely on trial-and-error approaches, with limited success to date.
Because of their unique properties, TIs can be created that conduct electricity more efficiently while also being much smaller that conventional wires or devices. They are ideal candidates to become quantum electronics devices, the Duke researchers said.
The "key" developed by the Duke investigators is a mathematical formulation that unlocks the data stored in a database of potential TI ingredients. It provides specific recipes for searching for TIs with the desired properties.
In November, Stefano Curtarolo, professor of mechanical engineering and materials sciences and physics at Duke's Pratt School of Engineering and founder of the Duke's Center for Materials Genomics, and colleagues reported the establishment of a materials genome repository (aflowlib.org) which allows scientists to stop using trial-and-error methods in the search for efficient alloys.
The project developed by the Duke engineers covers thousands of compounds, and provides detailed recipes for creating the most efficient combinations for a particular purpose, much like hardware stores mix different colors of paint to achieve the desired result. The project is the keystone of the newly formed Duke's Center for Materials Genomics.
"While extremely helpful and important, a database is intrinsically a sterile repository of information, without a soul and without life. We need to find the materials' 'genes,'" said Curtarolo. "We have developed what we call the 'topological descriptor,' that when applied to the database can provide the directions for producing crystals with desired properties."
While developing the key to this database, the team also discovered a new class of systems that could not have been anticipated without such a "genetic" approach.
The Duke research was reported online in the journal Nature Materials. The work was supported by the Office of Navy Research and the National Science Foundation.
The new descriptor developed by the Duke team basically can determine status of any specific combination of element under investigation. On one end of the spectrum, Curtarolo explained, is "fragile."
"We can rule those combinations out because, what good is a new type of crystal if it would be too difficult to grow, or if grown, would not likely survive?" Curtarolo said. A second group of combinations would be a middle group termed "feasible."
But what excites Curtarolo most are those combinations found to be "robust." These crystals are stable and can be easily and efficiently produced. Just as importantly, these crystals can be grown in different directions,which gives them the advantage of tailored electrical properties by simple growth processes.
While TIs are currently in the experimental stage, Curtarolo believes that with this new tool, scientists should have a powerful framework for engineering a wide variety of them.
Kesong Yang, a post-doctoral fellow in Curtarolo's laboratory, is first author of the paper. Other members of the team were Duke's Shidong Wang, Wahyu Setyawan, Pacific Northwest Laboratory and Marco Buongiorno Nardelli, University of North Texas and the Oak Ridge National Laboratory.
Citation: "A Search Model for Topological Insulators with High-Throughput Robustness Descriptors," Kesong Yang, et. al., Nature Materials [DOI: 10.1038/NMAT3332].
Richard Merritt | EurekAlert!
ADIR Project: Lasers Recover Valuable Materials
21.07.2017 | Fraunhofer-Institut für Lasertechnik ILT
High-tech sensing illuminates concrete stress testing
20.07.2017 | University of Leeds
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
21.07.2017 | Event News
19.07.2017 | Event News
12.07.2017 | Event News
21.07.2017 | Earth Sciences
21.07.2017 | Power and Electrical Engineering
21.07.2017 | Physics and Astronomy