Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



CARBON WORLDS
Fluorine grants white graphene new powers
by Staff Writers
Houston TX (SPX) Jul 18, 2017


Rice University graduate student Sruthi Radhakrishnan shows samples of pure hexagonal boron nitride and fluorinated hexagonal boron nitride. Fluorination turns the material known as white graphene, a common insulator, into a magnetic semiconductor that may be suitable for electronics and sensors in extreme environments. Image courtesy Jeff Fitlow/Rice University.

A little fluorine turns an insulating ceramic known as white graphene into a wide-bandgap semiconductor with magnetic properties. Rice University scientists said that could make the unique material suitable for electronics in extreme environments. A proof-of-concept paper from Rice researchers demonstrates a way to turn two-dimensional hexagonal boron nitride (h-BN) - aka white graphene - from an insulator to a semiconductor. The magnetism, they said, is an unexpected bonus.

Because the atomically thin material is an exceptional conductor of heat, the researchers suggested it may be useful for electronics in high-temperature applications, perhaps even as magnetic memory devices.

"Boron nitride is a stable insulator and commercially very useful as a protective coating, even in cosmetics, because it absorbs ultraviolet light," said Rice materials scientist Pulickel Ajayan, whose lab led the study. "There has been a lot of effort to try to modify its electronic structure, but we didn't think it could become both a semiconductor and a magnetic material. "So this is something quite different; nobody has seen this kind of behavior in boron nitride before," he said.

The researchers found that adding fluorine to h-BN introduced defects into its atomic matrix that reduced the bandgap enough to make it a semiconductor. The bandgap determines the electrical conductivity of a material.

"We saw that the gap decreases at about 5 percent fluorination," said Rice postdoctoral researcher and co-author Chandra Sekhar Tiwary. The gap gets smaller with additional fluorination, but only to a point. "Controlling the precise fluorination is something we need to work on. We can get ranges but we don't have perfect control yet. Because the material is atomically thin, one atom less or more changes quite a bit.

"In the next set of experiments, we want to learn to tune it precisely, atom by atom," he said.

They determined that tension applied by invading fluorine atoms altered the "spin" of electrons in the nitrogen atoms and affected their magnetic moments, the ghostly quality that determines how an atom will respond to a magnetic field like an invisible, nanoscale compass.

"We see angle-oriented spins, which are very unconventional for 2-D materials," said Rice graduate student and lead author Sruthi Radhakrishnan. Rather than aligning to form ferromagnets or canceling each other out, the spins are randomly angled, giving the flat material random pockets of net magnetism. These ferromagnet or anti-ferromagnet pockets can exist in the same swatch of h-BN, which makes them "frustrated magnets" with competing domains.

The researchers said their simple, scalable method can potentially be applied to other 2-D materials. "Making new materials through nanoengineering is exactly what our group is about," Ajayan said.

Co-authors of the paper are graduate students Carlos de los Reyes and Zehua Jin, chemistry lecturer Lawrence Alemany, postdoctoral researcher Vidya Kochat and Angel Marti, an associate professor of chemistry, of bioengineering and of materials science and nanoengineering, all of Rice; Valery Khabashesku of Rice and the Baker Hughes Center for Technology Innovation, Houston; Parambath Sudeep of Rice and the University of Toronto; Deya Das, Atanu Samanta and Rice alumnus Abhishek Singh of the Indian Institute of Science, Bangalore; Liangzi Deng and Ching-Wu Chu of the University of Houston; Thomas Weldeghiorghis of Louisiana State University and Ajit Roy of the Air Force Research Laboratories at Wright-Patterson Air Force Base.

Ajayan is chair of Rice's Department of Materials Science and NanoEngineering, the Benjamin M. and Mary Greenwood Anderson Professor in Engineering and a professor of chemistry.

Research paper

CARBON WORLDS
Flourine lends white graphene new qualities
Washington (UPI) Jul 14, 2017
With just a bit of fluorine, white graphene becomes a wide-bandgap semiconductor with magnetic properties. The new material could be used in electronics designed to perform under extreme conditions. White graphene is a two-dimensional atomic sheet of hexagonal boron nitride. Its hexagonal structure is similar to that of regular graphene, but the atomic layer is made up of boron nitride, ... read more

Related Links
Rice University
Carbon Worlds - where graphite, diamond, amorphous, fullerenes meet


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

CARBON WORLDS
NASA Awards Mission Systems Operations Contract

Counting calories in space

NASA Offers Space Station as Catalyst for Discovery in Washington

As the world embraces space, the 50 year old Outer Space Treaty needs adaptation

CARBON WORLDS
Hypersonic Travel Possibility Heats Up Massively After New Material Discovery

ISRO Develops Ship-Based Antenna System to Track Satellite Launches

Aerojet Rocketdyne tests Advanced Electric Propulsion System

After two delays, SpaceX launches broadband satellite for IntelSat

CARBON WORLDS
Curiosity Mars Rover Begins Study of Ridge Destination

For Moratorium on Sending Commands to Mars, Blame the Sun

Tributes to wetter times on Mars

Opportunity will spend three weeks at current location due to Solar Conjunction

CARBON WORLDS
China develops sea launches to boost space commerce

Chinese satellite Zhongxing-9A enters preset orbit

Chinese Space Program: From Setback, to Manned Flights, to the Moon

Chinese Rocket Fizzles Out, Puts Other Launches on Hold

CARBON WORLDS
LISA Pathfinder: bake, rattle and roll

ASTROSCALE Raises a Total of $25 Million in Series C Led by Private Companies

Korean Aerospace offices raided in anti-corruption probe

Iridium Poised to Make Global Maritime Distress and Safety System History

CARBON WORLDS
Japanese engineers develop headset-less VR system

Spacepath Communications Announces Innovative Frequency Converter Systems

Sorting complicated knots

Nature-inspired material uses liquid reinforcement

CARBON WORLDS
Molecular Outflow Launched Beyond Disk Around Young Star

Big, shape-shifting animals from the dawn of time

A New Search for Extrasolar Planets from the Arecibo Observatory

More to Life Than the Habitable Zone

CARBON WORLDS
Juno spots Jupiter's Great Red Spot

New Horizons Video Soars over Pluto's Majestic Mountains and Icy Plains

New evidence in support of the Planet Nine hypothesis

Juno Completes Flyby over Jupiter's Great Red Spot




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement