Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Carbyne morphs when stretched: Rice University calculations show carbon-atom chain would go metal to semiconductor

Carbyne turns from a metal to a semiconductor when stretched, according to calculations by Rice University scientists. Pulling on the ends would force the atoms to separate in pairs, opening a band gap. The chain of single carbon atoms would theoretically be the strongest material ever if it could be made reliably. Credit: Vasilii Artyukhov/Rice University
Carbyne turns from a metal to a semiconductor when stretched, according to calculations by Rice University scientists. Pulling on the ends would force the atoms to separate in pairs, opening a band gap. The chain of single carbon atoms would theoretically be the strongest material ever if it could be made reliably.

Credit: Vasilii Artyukhov/Rice University

Abstract:
Applying just the right amount of tension to a chain of carbon atoms can turn it from a metallic conductor to an insulator, according to Rice University scientists.

Carbyne morphs when stretched: Rice University calculations show carbon-atom chain would go metal to semiconductor

Houston, TX | Posted on July 21st, 2014

Stretching the material known as carbyne -- a hard-to-make, one-dimensional chain of carbon atoms -- by just 3 percent can begin to change its properties in ways that engineers might find useful for mechanically activated nanoscale electronics and optics.

The finding by Rice theoretical physicist Boris Yakobson and his colleagues appears in the American Chemical Society journal Nano Letters.

Until recently, carbyne has existed mostly in theory, though experimentalists have made some headway in creating small samples of the finicky material. The carbon chain would theoretically be the strongest material ever, if only someone could make it reliably.

The first-principle calculations by Yakobson and his co-authors, Rice postdoctoral researcher Vasilii Artyukhov and graduate student Mingjie Liu, show that stretching carbon chains activates the transition from conductor to insulator by widening the material's band gap. Band gaps, which free electrons must overcome to complete a circuit, give materials the semiconducting properties that make modern electronics possible.

In their previous work on carbyne, the researchers believed they saw hints of the transition, but they had to dig deeper to find that stretching would effectively turn the material into a switch.

Each carbon atom has four electrons available to form covalent bonds. In their relaxed state, the atoms in a carbyne chain would be more or less evenly spaced, with two bonds between them. But the atoms are never static, due to natural quantum uncertainty, which Yakobson said keeps them from slipping into a less-stable Peierls distortion.

"Peierls said one-dimensional metals are unstable and must become semiconductors or insulators," Yakobson said. "But it's not that simple, because there are two driving factors."

One, the Peierls distortion, "wants to open the gap that makes it a semiconductor." The other, called zero-point vibration (ZPV), "wants to maintain uniformity and the metal state."

Yakobson explained that ZPV is a manifestation of quantum uncertainty, which says atoms are always in motion. "It's more a blur than a vibration," he said. "We can say carbyne represents the uncertainty principle in action, because when it's relaxed, the bonds are constantly confused between 2-2 and 1-3, to the point where they average out and the chain remains metallic."

But stretching the chain shifts the balance toward alternating long and short (1-3) bonds. That progressively opens a band gap beginning at about 3 percent tension, according to the computations. The Rice team created a phase diagram to illustrate the relationship of the band gap to strain and temperature.

How carbyne is attached to electrodes also matters, Artyukhov said. "Different bond connectivity patterns can affect the metallic/dielectric state balance and shift the transition point, potentially to where it may not be accessible anymore," he said. "So one has to be extremely careful about making the contacts."

"Carbyne's structure is a conundrum," he said. "Until this paper, everybody was convinced it was single-triple, with a long bond then a short bond, caused by Peierls instability." He said the realization that quantum vibrations may quench Peierls, together with the team's earlier finding that tension can increase the band gap and make carbyne more insulating, prompted the new study.

"Other researchers considered the role of ZPV in Peierls-active systems, even carbyne itself, before we did," Artyukhov said. "However, in all previous studies only two possible answers were being considered: either 'carbyne is semiconducting' or 'carbyne is metallic,' and the conclusion, whichever one, was viewed as sort of a timeless mathematical truth, a static 'ultimate verdict.' What we realized here is that you can use tension to dynamically go from one regime to the other, which makes it useful on a completely different level."

Yakobson noted the findings should encourage more research into the formation of stable carbyne chains and may apply equally to other one-dimensional chains subject to Peierls distortions, including conducting polymers and charge/spin density-wave materials.

The Robert Welch Foundation, the U.S. Air Force Office of Scientific Research and the Office of Naval Research Multidisciplinary University Research Initiative supported the research. The researchers utilized the Data Analysis and Visualization Cyberinfrastructure (DAVinCI) supercomputer supported by the NSF and administered by Rice's Ken Kennedy Institute for Information Technology.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,920 undergraduates and 2,567 graduate students, Rice's undergraduate student-to-faculty ratio is just over 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance.

Follow Rice News and Media Relations via Twitter @RiceUNews

For more information, please click here

Contacts:
David Ruth
713-348-6327


Mike Williams
713-348-6728

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Read the abstract at:

Yakobson Research Group:

Rice University Department of Materials Science and NanoEngineering:

Related News Press

News and information

New thin film transistor may lead to flexible devices: Researchers engineer an electronics first, opening door to flexible electronics February 10th, 2016

Superconductivity: Footballs with no resistance - Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications February 9th, 2016

SUNY Poly and GLOBALFOUNDRIES Announce New $500M R&D Program in Albany To Accelerate Next Generation Chip Technology: Arrival of Second Cutting Edge EUV Lithography Tool Launches New Patterning Center That Will Generate Over 100 New High Tech Jobs at SUNY Poly February 9th, 2016

Electron's 1-D metallic surface state observed: A step for the prediction of electronic properties of extremely-fine metal nanowires in next-generation semiconductors February 9th, 2016

NEMS

Nano-photonics meets nano-mechanics: Controlling on-chip nano-optics by graphene nano-opto-mechanics January 22nd, 2016

Mechanical quanta see the light January 20th, 2016

Nanodevices at one-hundredth the cost: New techniques for building microelectromechanical systems show promise December 20th, 2015

Nano-mechanical study offers new assessment of silicon for next-gen batteries September 25th, 2015

Govt.-Legislation/Regulation/Funding/Policy

New thin film transistor may lead to flexible devices: Researchers engineer an electronics first, opening door to flexible electronics February 10th, 2016

SUNY Poly and GLOBALFOUNDRIES Announce New $500M R&D Program in Albany To Accelerate Next Generation Chip Technology: Arrival of Second Cutting Edge EUV Lithography Tool Launches New Patterning Center That Will Generate Over 100 New High Tech Jobs at SUNY Poly February 9th, 2016

Making sense of metallic glass February 9th, 2016

Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells February 9th, 2016

MEMS

Vesper Collaborates with GLOBALFOUNDRIES to Deliver First Piezoelectric MEMS Microphones: Acoustic sensing company works with top foundry to support mass-market consumer products January 21st, 2016

MEMS & Sensors Industry Group Previews “Internet of MEMS & Sensors” at CES 2016 -- Global industry association invites CE OEMS/integrators to conference track on January 7 January 6th, 2016

SITRI and Accelink Announce Cooperative Agreement on Opto-Electronic Communication December 31st, 2015

Nanodevices at one-hundredth the cost: New techniques for building microelectromechanical systems show promise December 20th, 2015

Chip Technology

New thin film transistor may lead to flexible devices: Researchers engineer an electronics first, opening door to flexible electronics February 10th, 2016

SUNY Poly and GLOBALFOUNDRIES Announce New $500M R&D Program in Albany To Accelerate Next Generation Chip Technology: Arrival of Second Cutting Edge EUV Lithography Tool Launches New Patterning Center That Will Generate Over 100 New High Tech Jobs at SUNY Poly February 9th, 2016

Electron's 1-D metallic surface state observed: A step for the prediction of electronic properties of extremely-fine metal nanowires in next-generation semiconductors February 9th, 2016

Metal oxide sandwiches: New option to manipulate properties of interfaces February 8th, 2016

Discoveries

New thin film transistor may lead to flexible devices: Researchers engineer an electronics first, opening door to flexible electronics February 10th, 2016

Making sense of metallic glass February 9th, 2016

Electron's 1-D metallic surface state observed: A step for the prediction of electronic properties of extremely-fine metal nanowires in next-generation semiconductors February 9th, 2016

Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells February 9th, 2016

Materials/Metamaterials

Superconductivity: Footballs with no resistance - Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications February 9th, 2016

Making sense of metallic glass February 9th, 2016

Graphene decharging and molecular shielding February 8th, 2016

A fast solidification process makes material crackle February 8th, 2016

Announcements

New thin film transistor may lead to flexible devices: Researchers engineer an electronics first, opening door to flexible electronics February 10th, 2016

SUNY Poly and GLOBALFOUNDRIES Announce New $500M R&D Program in Albany To Accelerate Next Generation Chip Technology: Arrival of Second Cutting Edge EUV Lithography Tool Launches New Patterning Center That Will Generate Over 100 New High Tech Jobs at SUNY Poly February 9th, 2016

Making sense of metallic glass February 9th, 2016

Electron's 1-D metallic surface state observed: A step for the prediction of electronic properties of extremely-fine metal nanowires in next-generation semiconductors February 9th, 2016

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

New thin film transistor may lead to flexible devices: Researchers engineer an electronics first, opening door to flexible electronics February 10th, 2016

Superconductivity: Footballs with no resistance - Indications of light-induced lossless electricity transmission in fullerenes contribute to the search for superconducting materials for practical applications February 9th, 2016

Making sense of metallic glass February 9th, 2016

Electron's 1-D metallic surface state observed: A step for the prediction of electronic properties of extremely-fine metal nanowires in next-generation semiconductors February 9th, 2016

Military

Scientists guide gold nanoparticles to form 'diamond' superlattices: DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond February 4th, 2016

Researchers develop completely new kind of polymer: Hybrid polymers could lead to new concepts in self-repairing materials, drug delivery and artificial muscles January 30th, 2016

Nano-coating makes coaxial cables lighter: Rice University scientists replace metal with carbon nanotubes for aerospace use January 28th, 2016

Scientists build a neural network using plastic memristors: A group of Russian and Italian scientists have created a neural network based on polymeric memristors -- devices that can potentially be used to build fundamentally new computers January 28th, 2016

Grants/Awards/Scholarships/Gifts/Contests/Honors/Records

Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells February 9th, 2016

Scientists create laser-activated superconductor February 8th, 2016

UTHealth research looks at nanotechnology to help prevent preterm birth February 7th, 2016

Graphene is strong, but is it tough? Berkeley Lab scientists find that polycrystalline graphene is not very resistant to fracture February 7th, 2016

Photonics/Optics/Lasers

Scientists create laser-activated superconductor February 8th, 2016

Nanoscale cavity strongly links quantum particles: Single photons can quickly modify individual electrons embedded in a semiconductor chip and vice versa February 8th, 2016

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Scientists guide gold nanoparticles to form 'diamond' superlattices: DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond February 4th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic