Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Flat boron by the numbers

01.02.2013
Rice University researchers calculate what it would take to make new two-dimensional material
It would be a terrible thing if laboratories striving to grow graphene from carbon atoms kept winding up with big pesky diamonds.

“That would be trouble, cleaning out the diamonds so you could do some real work,” said Rice University theoretical physicist Boris Yakobson, chuckling at the absurd image.

Yet something like that keeps happening to experimentalists working to grow two-dimensional boron. Boron atoms have a strong preference to clump into three-dimensional shapes rather than assemble into pristine single-atom sheets, like carbon does when it becomes graphene. And boron clumps aren’t nearly as sparkly.

Yakobson and his Rice colleagues have made progress toward 2-D boron through theoretical work that suggests the most practical ways to make the material and put it to work. Earlier calculations by the group indicated 2-D born would conduct electricity better than graphene.

Through first-principle calculations of the interaction of boron atoms with various substrates, the team came up with several possible paths experimentalists may take toward 2-D boron. Yakobson feels the work may point the way toward other useful two-dimensional materials.

The Rice team’s results appear this week in the journal Angewandte Chemie International Edition. Rice graduate student Yuanyue Liu and research scientist Evgeni Penev are co-authors of the paper.

Yakobson’s lab first reported in a Nano Letters paper last year that unlike graphene, 2-D boron rolled into a nanotube would always be metallic. Also unlike graphene, the atomic arrangement can change without changing the nature of the material. Instead of the steady rank-and-file of hexagons in a perfect graphene sheet, 2-D boron consists of triangles. But boron could have vacancies – missing atoms – without affecting its properties.

That’s the theory. The problem that remains is how to make the stuff.

“We are, perhaps, so close,” Penev said. “Here we have conceived a material that resembles graphene, but is always conductive no matter what form it takes. What we’re doing now is exploring different possibilities to connect our theories with reality.”

The best method, they calculated, might be to feed boron into a furnace with silver or gold substrates in a process called chemical vapor deposition, commonly used to make graphene. The substrate is important, Penev said, because the atoms have to spill onto the surface and stick, but not too strongly.

“You have to have a substrate that doesn’t want to dissolve boron,” he said. “On the other hand, you want a substrate that doesn’t bind too strongly. You should be able to detach the boron layer.”

Then, like graphene, these atom-thick boron sheets could be applied to other surfaces for testing and, ultimately, for use in applications.

The study also calculated methods for creating sheets via saturation of boron atoms on the surface of boride substrates, and the evaporation of metal atoms from metal borides that leaves just the target atoms in a sheet.

“There are a lot of reasons boron could be interesting,” said Liu, the paper’s first author. “Boron is carbon’s neighbor on the periodic table, with one less electron, which might bring in lots of new physics and chemistry, especially on the nanoscale. For example, 2-D boron is more conductive than graphene because of its unique electronic structure and atomic arrangement.

“In fact, comparing (boron) with graphene is very helpful,” he said. “The state-of-art synthesis methods for graphene provide us good templates to explore 2-D boron synthesis.”

Yakobson is thinking a step beyond the current work. “There are many groups, at Rice and elsewhere, working on 2-D boron,” he said. “To appreciate this work, you have to stand back and contrast it with graphene; in some sense, the synthesis of graphene is trivial.

“Why? Because graphene is a God-given material,” he said. “It forms at the global minimum (energy) for carbon atoms – they go there willingly. But boron is a different story. It does not have a planar form as a global minimum, which makes it a really subtle problem. The novelty in this work is that we’re trying to trick it into building a two-dimensional motif instead of three.”

The search for 2-D materials with varying qualities is hot right now; another new paper from Rice on a hybrid graphene-hexagonal boron nitride shows the need for a 2-D semiconductor to complement the material’s conducting and insulating elements.

Yakobson hopes his study serves as a guideline for practical routes to other novel materials. “Now that there is a growing interest in a variety of 2-D materials, this may be a template,” he said.

Yakobson is Rice’s Karl F. Hasselmann Professor of Mechanical Engineering and Materials Science and professor of chemistry.

The Department of Energy (DOE) supported the research. Computations were performed on the National Science Foundation-funded Data Analysis and Visualization Cyberinfrastructure at Rice, along with resources at the National Institute for Computational Sciences and the DOE’s National Energy Research Scientific Computing Center.
Read the abstract at http://dx.doi.org/10.1002/anie.201207972

This news release can be found online at
http://news.rice.edu/2013/01/31/flat-boron-by-the-numbers/


Related Materials:

Yakobson Research Group:
http://biygroup.blogs.rice.edu/archives/category/group-news


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 3,708 undergraduates and 2,374 graduate students, Rice’s undergraduate student-to-faculty ratio is 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. To read “What they’re saying about Rice,” go to http://tinyurl.com/AboutRiceU.

David Ruth | EurekAlert!
Further information:
http://www.rice.edu

Further reports about: 2-D pictures Flat Terrain big pesky diamonds boron atoms graphene hexagons

More articles from Life Sciences:

nachricht Individual Receptors Caught at Work
19.10.2017 | Julius-Maximilians-Universität Würzburg

nachricht Rapid environmental change makes species more vulnerable to extinction
19.10.2017 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>