“We could potentially create new materials with unusual properties that have never existed,”
By creating atomic chains in a two-dimensional crystal, researchers at Penn State believe they have found a way to control the direction of materials properties in two and three dimensional crystals with implications in sensing, optoelectronics and next-generation electronics applications.
Whether an alloy has a random arrangement of atoms or one that is ordered can have large effects on a material’s properties. In a new paper published online in the journal Nano Letters, Nasim Alem, assistant professor of materials science and engineering, and colleagues at Penn State used a combination of simulations and scanning transmission electron microscopy imaging to determine the atomic structure of an ordered alloy of molybdenum, tungsten and sulfur. They determined that fluctuations in the amount of available sulfur were responsible for the creation of atomic chains of either molybdenum or tungsten.
“We discovered how chains form in a two-dimensional alloy as a result of fluctuations in the amount of a particular precursor, in this case sulfur,” Alem said. “Normally, when we combine atoms of different elements, we don’t know how to control where the atoms will go. But we have found a mechanism to give order to the atoms, which in turn introduces control of the properties, not only heat transport, as is the case in this work, but also electronic, chemical or magnetic properties in other alloy cases. If you know the mechanism, you can apply it to arrange the atoms in a wide range of alloys in 2D crystals across the Periodic Table.”
In the case of the molybdenum, tungsten and sulfur alloy, they showed that the electronic properties were the same in every direction, but using simulations they predict that the thermal transport properties are smaller perpendicular to the chains or stripes.
“We didn’t know why this crystal forms an ordered structure, so we worked with my colleague Dr. Vin Crespi to understand the underlying physics that causes order in this crystal. Our calculations show it was the fluctuations in the third element, sulfur, that was determining how the chains formed,” Alem said.
Vincent H. Crespi, Distinguished Professor of Physics, and professor of chemistry and materials science and engineering who developed the theoretical understanding of the phenomenon, said, “Although the interior of the flake is indifferent to whether molybdenum or tungsten occupies any site in the crystal lattice, the edge of the growing crystal does care: Depending on how much sulfur is available at a given location, the edge will prefer to be either 100% molybdenum or 100% tungsten. So as the availability of sulfur randomly varies during growth, the system alternately lays down rows of molybdenum or tungsten. We think this may be a general mechanism to create stripe-like structures in 2D materials.”
Amin Aziz, who is a Ph.D. candidate in Alem’s group and lead author on the Nano Letters paper, produced the STEM imaging and spectroscopy that showed the fine atomic structure of the alloy samples and their electronic properties.
“When we are able to directly image constitutive atoms of a substance, see how they interact with each other at the atomic level and try to understand the origins of such behaviors, we could potentially create new materials with unusual properties that have never existed,” said Azizi.
A team led by Mauricio Terrones, professor of physics, produced samples of this ordered alloy by vaporizing powders of all three elements, called precursors, under high heat.
Learn more: Controlling The Properties Of Matter In Two-Dimensional Crystals
The Latest on: Atomic chains
[google_news title=”” keyword=”atomic chains” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Atomic chains
- CNNC provides nuclear energy solutions for global energy transitionon April 27, 2024 at 6:20 am
Photo: Courtesy of China National Nuclear Corporation "Currently, the world economy is gradually recovering, and the energy industry is accelerating its green and low-carbon trans ...
- Boy Kills World review: You deserve better than thison April 26, 2024 at 12:00 pm
Boy Kills World wants to be your next favorite cult action movie, but it instead makes you want to watch the films it so shamelessly rips off.
- A history of the Statue of Liberty getting destroyed or distorted in movie posterson April 26, 2024 at 10:31 am
This inaugural piece of "Civil War" marketing continues a long-running promotional trend for movie posters in distorting the Statue of Liberty. Over the years, decimating this iconic American landmark ...
- Grim anniversary: Zaporizhzhia nuclear plant must not become the next Chornobylon April 26, 2024 at 3:40 am
Authors: Shaun Burnie, Jan Vande Putte, Daryna Rogachuk, Greenpeace Green Reconstruction Ukraine Project Chornobyl is one of the most recognised synonyms for disaster in the world. Its legacy is to ...
- Nuclear Power’s Lethal, Larcenous End Gameon April 25, 2024 at 10:55 pm
For the first time since 1954, no large new atomic reactors are under construction or on order in the United States. On March 1, 2024, Vogtle Unit ...
- Where Is Everybody in Our Universe?on April 25, 2024 at 9:33 am
In Exoplanets, astronomer Michael Summers and physicist James Trefil explore remarkable recent discoveries: planets revolving around pulsars, planets made of diamond, planets that are mostly water, ...
- Nuclear Power’s Expansion Risks Collapse on Widening Conflictson April 25, 2024 at 6:32 am
Atomic power’s potential as a clean-energy source forestalling climate change is increasingly at risk, with new data suggesting nuclear growth could be threatened by spreading geopolitical instability ...
- Dutton’s atomic bet threatens Coalition chain reaction over climateon April 24, 2024 at 11:21 pm
Rather than keep the heat on Labor’s handling of the cost-of-living pain as inflation stays high, the opposition leader’s nuclear venture risks becoming the story.
- Rare Earths Reserves: Top 8 Countries (Updated 2024)on April 24, 2024 at 1:55 pm
Rare earths prices soared to their highest level in 20 months, according to OilPrice.com, in early Q3 2023 coinciding with a temporary production halt in Myanmar, which accounted for 38 percent of ...
via Bing News