Nanotechnology Now







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

Leti to Offer Updates on Silicon Photonics Successes at OFC in LA February 27th, 2015

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Untangling DNA with a droplet of water, a pipet and a polymer: With the 'rolling droplet technique,' a DNA-injected water droplet rolls like a ball over a platelet, sticking the DNA to the plate surface February 27th, 2015

Maximum Precision in 3D Printing: New complete solution makes additive manufacturing standard for microfabrication February 26th, 2015

NEMS

Optical nanoantennas set the stage for a NEMS lab-on-a-chip revolution February 24th, 2015

Piezoelectricity in a 2-D semiconductor: Berkeley Lab researchers discovery of piezoelectricty in molybdenum disulfide holds promise for future MEMS December 22nd, 2014

LetiDays Grenoble to Present Multiple Perspectives on Development, Challenges and Markets for the IoT April 14th, 2014

Columbia engineers make world's smallest FM radio transmitter: Team demonstrates new application of graphene using positive feedback November 18th, 2013

Govt.-Legislation/Regulation/Funding/Policy

Warming up the world of superconductors: Clusters of aluminum metal atoms become superconductive at surprisingly high temperatures February 25th, 2015

SUNY Poly CNSE Researchers and Corporate Partners to Present Forty Papers at Globally Recognized Lithography Conference: SUNY Poly CNSE Research Group Awarded Both ‘Best Research Paper’ and ‘Best Research Poster’ at SPIE Advanced Lithography 2015 forum February 25th, 2015

European roadmap for graphene science and technology published February 25th, 2015

Dendrite eraser: New electrolyte rids batteries of short-circuiting fibers: Solution enables a battery with both high efficiency & current density February 24th, 2015

MEMS

MEMS/Sensors Drive IoT/E Innovation in Europe: MEMS Executive Congress Europe Speakers Explore Internet of Things/Everything in Automotive, Consumer, Industrial Markets, 9-10, March in Copenhagen February 9th, 2015

STMicroelectronics Leads European Research Project to Develop Next-Generation Optical MEMS: Extension to a project launched in 2013 builds on current efforts to enable technologies for next-generation applications February 4th, 2015

Entegris Launches Dispense System Optimized for 3D and MEMS Applications: New IntelliGen® MV system delivers process efficiencies and defect reduction in dispensing mid-viscosity fluids February 3rd, 2015

CNSE's Smart System Technology & Commercialization Center Successfully Recertifies as ISO 9001:2008 January 12th, 2015

Chip Technology

New nanowire structure absorbs light efficiently: Dual-type nanowire arrays can be used in applications such as LEDs and solar cells February 25th, 2015

SUNY Poly CNSE Researchers and Corporate Partners to Present Forty Papers at Globally Recognized Lithography Conference: SUNY Poly CNSE Research Group Awarded Both ‘Best Research Paper’ and ‘Best Research Poster’ at SPIE Advanced Lithography 2015 forum February 25th, 2015

Ultra-thin nanowires can trap electron 'twisters' that disrupt superconductors February 24th, 2015

Silicon Catalyst Announces Partnership With imec to Support Semiconductor Start-Ups February 23rd, 2015

Discoveries

Leti to Offer Updates on Silicon Photonics Successes at OFC in LA February 27th, 2015

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Untangling DNA with a droplet of water, a pipet and a polymer: With the 'rolling droplet technique,' a DNA-injected water droplet rolls like a ball over a platelet, sticking the DNA to the plate surface February 27th, 2015

Graphene shows potential as novel anti-cancer therapeutic strategy: University of Manchester scientists have used graphene to target and neutralise cancer stem cells while not harming other cells February 26th, 2015

Materials/Metamaterials

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Graphene shows potential as novel anti-cancer therapeutic strategy: University of Manchester scientists have used graphene to target and neutralise cancer stem cells while not harming other cells February 26th, 2015

In quest for better lithium-air batteries, chemists boost carbon's stability: Nanoparticle coatings improve stability, cyclability of '3DOm' carbon February 25th, 2015

Learning by eye: Silicon micro-funnels increase the efficiency of solar cells February 25th, 2015

Announcements

Leti to Offer Updates on Silicon Photonics Successes at OFC in LA February 27th, 2015

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Untangling DNA with a droplet of water, a pipet and a polymer: With the 'rolling droplet technique,' a DNA-injected water droplet rolls like a ball over a platelet, sticking the DNA to the plate surface February 27th, 2015

Graphene shows potential as novel anti-cancer therapeutic strategy: University of Manchester scientists have used graphene to target and neutralise cancer stem cells while not harming other cells February 26th, 2015

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

Moving molecule writes letters: Caging of molecules allows investigation of equilibrium thermodynamics February 27th, 2015

Untangling DNA with a droplet of water, a pipet and a polymer: With the 'rolling droplet technique,' a DNA-injected water droplet rolls like a ball over a platelet, sticking the DNA to the plate surface February 27th, 2015

Real-time observation of bond formation by using femtosecond X-ray liquidography February 26th, 2015

Graphene shows potential as novel anti-cancer therapeutic strategy: University of Manchester scientists have used graphene to target and neutralise cancer stem cells while not harming other cells February 26th, 2015

Military

Simulating superconducting materials with ultracold atoms: Rice physicists build superconductor analog, observe antiferromagnetic order February 23rd, 2015

Perfect colors, captured with one ultra-thin lens: No need for color correction -- Harvard physicists' flat optics, using nanotechnology, get it right the first time February 19th, 2015

Penn researchers develop new technique for making molybdenum disulfide: Extra control over monolayer material with advantages over graphene February 19th, 2015

New nanogel for drug delivery: Self-healing gel can be injected into the body and act as a long-term drug depot February 19th, 2015

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

Rice's Stephan Link honored for nanoscience research: The Welch Foundation honors ‘rising star’ with $100,000 Hackerman Award February 26th, 2015

Cutting-edge technology optimizes cancer therapy with nanomedicine drug combinations: UCLA bioengineers develop platform that offers personalized approach to treatment February 24th, 2015

QD Vision Named Edison Award Finalist for Innovative Color IQ™ Quantum Dot Technology February 23rd, 2015

Rosetta Team Wins the National Space Society's Science and Engineering Space Pioneer Award February 23rd, 2015

Photonics/Optics/Lasers

Leti to Offer Updates on Silicon Photonics Successes at OFC in LA February 27th, 2015

Rice's Stephan Link honored for nanoscience research: The Welch Foundation honors ‘rising star’ with $100,000 Hackerman Award February 26th, 2015

Maximum Precision in 3D Printing: New complete solution makes additive manufacturing standard for microfabrication February 26th, 2015

Learning by eye: Silicon micro-funnels increase the efficiency of solar cells February 25th, 2015

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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE