Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Physicists Heat Freestanding Graphene to Control Curvature of Ripples

19.09.2014

Discovery represents advance in understanding of conductive material

An international team of physicists, led by a research group at the University of Arkansas, has discovered that heating can be used to control the curvature of ripples in freestanding graphene.


Mehdi Neek-Amal, University of Antwerp

Height of the initial buckled graphene state with the bias voltage set to 3 V and the central temperature set to 300 K.

The finding provides fundamental insight into understanding the influence temperature exerts on the dynamics of freestanding graphene. This may drive future applications of the flexible circuits of consumer devices such as cell phones and digital cameras.

While freestanding graphene offers promise as a replacement for silicon and other materials in microprocessors and next-generation energy devices, much remains unknown about its mechanical and thermal properties.

The research team published its findings on Wednesday, Sept. 17, in a paper titled “Thermal mirror buckling in freestanding graphene locally controlled by scanning tunneling microscopy” in the online journal Nature Communications, a publication of the journal Nature.

Previously, scientists have used electric voltage to cause large movements and sudden changes in the curvature of the ripples in freestanding graphene, said Paul Thibado, professor of physics at the University of Arkansas. In this paper, the team showed that an alternative method, thermal load, can be used to control these movements.

“Imagine taking a racquetball and cutting it in half,” said Thibado, an expert in experimental condensed matter physics. “You could invert it by pressing on it. That’s what we did here with a cross-section of a single ripple of freestanding graphene at the nanometer scale. Most materials expand when you heat them. Graphene contracts which is very unusual. So when we heated this cross-section, instead of expanding, it contracted, and that thermal stress caused it to buckle in the opposite direction.”

Graphene, discovered in 2004, is a one-atom-thick sheet of graphite. Electrons moving through graphite have mass and encounter resistance, while electrons moving through graphene are massless, and therefore travel much more freely. This makes graphene an excellent candidate material for use in meeting future energy needs and the fabrication of quantum computers, which make enormous calculations with little energy use.

The study was led by Peng Xu, formerly a postdoctoral research associate in the Department of Physics at the University of Arkansas and currently a postdoctoral research associate at the University of Maryland.

Xu and Thibado used scanning tunneling microscopy, which produces images of individual atoms on a surface, combined with large-scale molecular dynamic simulations to demonstrate the thermal mirror buckling.

In the paper, the third published in a major journal by the research team in 2014, they propose a concept for a new instrument that capitalizes on the control of the mirror buckling: a nanoscale electro-thermal-mechanical device.

Such a device would provide an alternative to microelectromechanical systems, which are tiny machines that are activated electrically. The advantage of this nanoscale electro-thermal-mechanical device would be the ability to change its output using electricity or heat. In addition, thermal loads can provide a significantly larger force.

The study, funded by the Office of Naval Research and the National Science Foundation, was conducted primarily through a research partnership between the University of Arkansas and the University of Antwerp in Belgium.

The results were obtained through a collaborative effort with University of Arkansas physics graduate students Steven D. Barber, James Kevin Schoelz and Matthew L. Ackerman; Mehdi Neek-Amal of the University of Antwerp and Shahid Rajaee Teacher Training University in Iran, Ali Sadeghi of the University of Basel in Switzerland and Francois Peeters of the University of Antwerp.

Contact:
Paul Thibado, professor, physics
J. William Fulbright College of Arts and Sciences
479-575-7932, thibado@uark.edu

Chris Branam | newswise

More articles from Materials Sciences:

nachricht Switched-on DNA
20.02.2017 | Arizona State University

nachricht Using a simple, scalable method, a material that can be used as a sensor is developed
15.02.2017 | University of the Basque Country

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>