Date | 12th, Apr 2019 |
---|
Home > Press > 2D borophene gets a closer look: Rice, Northwestern find new ways to image, characterize unique material
Abstract: Graphene can come from graphite. But borophene? There's no such thing as borite.
Houston, TX | Posted on April 11th, 2019
Unlike its carbon cousin, two-dimensional borophene can't be reduced from a larger natural form. Bulk boron is usually only found in combination with other elements, and is certainly not layered, so borophene has to be made from the atoms up. Even then, the borophene you get may not be what you need.
For that reason, researchers at Rice and Northwestern universities have developed a method to view 2D borophene crystals, which can have many lattice configurations -- called polymorphs -- that in turn determine their characteristics.
Knowing how to achieve specific polymorphs could help manufacturers incorporate borophene with desirable electronic, thermal, optical and other physical properties into products.
Boris Yakobson, a materials physicist at Rice's Brown School of Engineering, and materials scientist Mark Hersam of Northwestern led a team that not only discovered how to see the nanoscale structures of borophene lattices but also built theoretical models that helped characterize the crystalline forms.
Their results are published in Nature Communications.
Borophene remains hard to make in even small quantities. If and when it can be scaled up, manufacturers will likely want to fine-tune it for applications. What the Rice and Northwestern teams learned will help in that regard.
Graphene takes a single form � an array of hexagons, like chicken wire � but perfect borophene is a grid of triangles. However, borophene is a polymorph, a material that can have more than one crystal structure. Vacancies that leave patterns of "hollow hexagons" in a borophene lattice determine its physical and electrical properties.
Yakobson said there could theoretically be more than 1,000 forms of borophene, each with unique characteristics.
"It has many possible patterns and networks of atoms being connected in the lattice," he said.
The project started at Hersam's Northwestern lab, where researchers modified the blunt tip of an atomic force microscope with a sharp tip of carbon and oxygen atoms. That gave them the ability to scan a flake of borophene to sense electrons that correspond to covalent bonds between boron atoms. They used a similarly modified scanning tunneling microscope to find hollow hexagons where a boron atom had gone missing.
Scanning flakes grown on silver substrates under various temperatures via molecular-beam epitaxy showed them a range of crystal structures, as the changing growth conditions altered the lattice.
�Modern microscopy is very sophisticated, but the result is, unfortunately, that the image you get is generally difficult to interpret," Yakobson said. "That is, it's hard to say an image corresponds to a particular atomic lattice. It's far from obvious, but that's where theory and simulations come in."
Yakobson's team used first-principle simulations to determine why borophene took on particular structures based on calculating the interacting energies of both boron and substrate atoms. Their models matched many of the borophene images produced at Northwestern.
"We learned from the simulations that the degree of charge transfer from the metal substrate into borophene is important," he said. "How much of this is happening, from nothing to a lot, can make a difference."
The researchers confirmed through their analysis that borophene is also not an epitaxial film. In other words, the atomic arrangement of the substrate doesn't dictate the arrangement or rotational angle of borophene.
The team produced a phase diagram that lays out how borophene is likely to form under certain temperatures and on a variety of substrates, and noted their microscopy advances will be valuable for finding the atomic structures of emerging 2D materials.
Looking to the future, Hersam said, "The development of methods to characterize and control the atomic structure of borophene is an important step toward realizing the many proposed applications of this material, which range from flexible electronics to emerging topics in quantum information sciences."
Xiaolong Liu of Northwestern and Luqing Wang of Rice are lead authors of the paper. Co-authors are Shaowei Li and Matthew Rahn of Northwestern. Yakobson is the Karl F. Hasselmann Professor of Materials Science and NanoEngineering and a professor of chemistry at Rice. Hersam is the Walter P. Murphy Professor of Materials Science and Engineering at Northwestern.
The Office of Naval Research, the National Science Foundation, the Department of Energy Office of Science and the Northwestern University International Institute for Nanotechnology supported the research.
####
About Rice UniversityLocated 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 3,962 undergraduates and 3,027 graduate students, Rice�s undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 2 for quality of life by the Princeton Review. Rice is also rated as a 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 Ruth713-348-6327
Mike Williams713-348-6728
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.
Gold soaks up boron, spits out borophene:
George R. Brown School of Engineering:
Imaging
An artificial intelligence probe help see tumor malignancy July 1st, 2022
News and information
Two opposing approaches could give lithium-sulfur batteries a leg up over lithium-ion July 1st, 2022
Efficiently processing high-quality periodic nanostructures with ultrafast laser July 1st, 2022
Photonic synapses with low power consumption and high sensitivity are expected to integrate sensing-memory-preprocessing capabilities July 1st, 2022
Flexible Electronics
�Fruitcake� structure observed in organic polymers June 3rd, 2022
2 Dimensional Materials
Controlled synthesis of crystal flakes paves path for advanced future electronics June 17th, 2022
Solving the puzzle of 2D disorder: An interdisciplinary team developed a new method to characterize disorder in 2D materials June 17th, 2022
UBCO researchers change the game when it comes to activity tracking: Flexible, highly sensitive motion device created by extrusion printing June 17th, 2022
Bumps could smooth quantum investigations: Rice University models show unique properties of 2D materials stressed by contoured substrates June 10th, 2022
Graphene/ Graphite
OCSiAl expands its graphene nanotube production capacities to Europe June 17th, 2022
Bumps could smooth quantum investigations: Rice University models show unique properties of 2D materials stressed by contoured substrates June 10th, 2022
Govt.-Legislation/Regulation/Funding/Policy
Solving the solar energy storage problem with rechargeable batteries that can convert and store energy at once June 24th, 2022
Boron nitride nanotube fibers get real: Rice lab creates first heat-tolerant, stable fibers from wet-spinning process June 24th, 2022
UBCO researchers change the game when it comes to activity tracking: Flexible, highly sensitive motion device created by extrusion printing June 17th, 2022
University of Illinois Chicago joins Brookhaven Lab's Quantum Center June 10th, 2022
Possible Futures
Sieving carbons: Ideal anodes for high-energy sodium-ion batteries July 1st, 2022
An artificial intelligence probe help see tumor malignancy July 1st, 2022
Photon-controlled diode: an optoelectronic device with a new signal processing behavior July 1st, 2022
Chip Technology
Photon-controlled diode: an optoelectronic device with a new signal processing behavior July 1st, 2022
Photonic synapses with low power consumption and high sensitivity are expected to integrate sensing-memory-preprocessing capabilities July 1st, 2022
Optical computing/Photonic computing
Photon-controlled diode: an optoelectronic device with a new signal processing behavior July 1st, 2022
Efficiently processing high-quality periodic nanostructures with ultrafast laser July 1st, 2022
Photonic synapses with low power consumption and high sensitivity are expected to integrate sensing-memory-preprocessing capabilities July 1st, 2022
Nanoelectronics
Controlled synthesis of crystal flakes paves path for advanced future electronics June 17th, 2022
Eyebrow-raising: Researchers reveal why nanowires stick to each other February 11th, 2022
Visualizing temperature transport: An unexpected technique for nanoscale characterization November 19th, 2021
Announcements
Two opposing approaches could give lithium-sulfur batteries a leg up over lithium-ion July 1st, 2022
Efficiently processing high-quality periodic nanostructures with ultrafast laser July 1st, 2022
Photonic synapses with low power consumption and high sensitivity are expected to integrate sensing-memory-preprocessing capabilities July 1st, 2022
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Sieving carbons: Ideal anodes for high-energy sodium-ion batteries July 1st, 2022
An artificial intelligence probe help see tumor malignancy July 1st, 2022
Photon-controlled diode: an optoelectronic device with a new signal processing behavior July 1st, 2022
Military
Boron nitride nanotube fibers get real: Rice lab creates first heat-tolerant, stable fibers from wet-spinning process June 24th, 2022
Bumps could smooth quantum investigations: Rice University models show unique properties of 2D materials stressed by contoured substrates June 10th, 2022
Nanostructured fibers can impersonate human muscles June 3rd, 2022
Lightening up the nanoscale long-wavelength optoelectronics May 13th, 2022
Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records
Solving the solar energy storage problem with rechargeable batteries that can convert and store energy at once June 24th, 2022
Boron nitride nanotube fibers get real: Rice lab creates first heat-tolerant, stable fibers from wet-spinning process June 24th, 2022
Photonics/Optics/Lasers
Photon-controlled diode: an optoelectronic device with a new signal processing behavior July 1st, 2022
Efficiently processing high-quality periodic nanostructures with ultrafast laser July 1st, 2022
Photonic synapses with low power consumption and high sensitivity are expected to integrate sensing-memory-preprocessing capabilities July 1st, 2022
Research partnerships
New technology helps reveal inner workings of human genome June 24th, 2022
Boron nitride nanotube fibers get real: Rice lab creates first heat-tolerant, stable fibers from wet-spinning process June 24th, 2022
Quantum nanoscience
Bumps could smooth quantum investigations: Rice University models show unique properties of 2D materials stressed by contoured substrates June 10th, 2022
UCI scientists turn a hydrogen molecule into a quantum sensor: New technique enables precise measurement of electrostatic properties of materials April 22nd, 2022