Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Buckyballs on gold are less exotic than graphene

Using density functional theory and measurement data from spin-resolved photoemission, the team investigated the origin of the repeating Au(111) bands and resolved them as deep surface resonances. These resonances lead to an onion-like Fermi surface of Au(111).
CREDIT
HZB
Using density functional theory and measurement data from spin-resolved photoemission, the team investigated the origin of the repeating Au(111) bands and resolved them as deep surface resonances. These resonances lead to an onion-like Fermi surface of Au(111). CREDIT HZB

Abstract:
Graphene consists of carbon atoms that crosslink in a plane to form a flat honeycomb structure. In addition to surprisingly high mechanical stability, the material has exciting electronic properties: The electrons behave like massless particles, which can be clearly demonstrated in spectrometric experiments. Measurements reveal a linear dependence of energy on momentum, namely the so-called Dirac cones - two lines that cross without a band gap - i.e. an energy difference between electrons in the conduction band and those in the valence bands.

Buckyballs on gold are less exotic than graphene

Berlin, Germany | Posted on July 22nd, 2022

Variants in graphene architecture
Artificial variants of graphene architecture are a hot topic in materials research right now. Instead of carbon atoms, quantum dots of silicon have been placed, ultracold atoms have been trapped in the honeycomb lattice with strong laser fields, or carbon monoxide molecules have been pushed into place on a copper surface piece by piece with a scanning tunneling microscope, where they could impart the characteristic graphene properties to the electrons of the copper.

Artificial graphene with buckyballs?
A recent study suggested that it is infinitely easier to make artificial graphene using C60 molecules called buckyballs. Only a uniform layer of these needs to be vapor-deposited onto gold for the gold electrons to take on the special graphene properties. Measurements of photoemission spectra appeared to show a kind of Dirac cone.

Analysis of band structures at BESSY II
"That would be really quite amazing," says Dr. Andrei Varykhalov, of HZB, who heads a photoemission and scanning tunneling microscopy group. "Because the C60 molecule is absolutely nonpolar, it was hard for us to imagine how such molecules would exert a strong influence on the electrons in the gold." So Varykhalov and his team launched a series of measurements to test this hypothesis.

In tricky and detailed analyses, the Berlin team was able to study C60 layers on gold over a much larger energy range and for different measurement parameters. They used angle-resolved ARPES spectroscopy at BESSY II, which enables particularly precise measurements, and also analysed electron spin for some measurements.

Normal behavior
"We see a parabolic relationship between momentum and energy in our measured data, so it's a very normal behavior. These signals come from the electrons deep in the substrate (gold or copper) and not the layer, which could be affected by the buckyballs," explains Dr. Maxim Krivenkov, lead author of the study. The team was also able to explain the linear measurement curves from the previous study. "These measurement curves merely mimic the Dirac cones; they are an artifact, so to speak, of a deflection of the photoelectrons as they leave the gold and pass through the C60 layer," Varykhalov explains. Therefore, the buckyball layer on gold cannot be considered an artificial graphene.

####

For more information, please click here

Contacts:
Media Contact

Antonia Roetger
Helmholtz-Zentrum Berlin für Materialien und Energie

Office: 0049-308-062-43733

Expert Contact

Dr. Maxim Krivenkov
Helmholtz-Zentrum Berlin

Copyright © Helmholtz-Zentrum Berlin für Materialien und Energie

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

ARTICLE TITLE

Related News Press

Graphene/ Graphite

Graphene grows – and we can see it March 24th, 2023

2 Dimensional Materials

Graphene grows – and we can see it March 24th, 2023

HKUMed invents a novel two-dimensional (2D) ultrasound-responsive antibacterial nano-sheets to effectively address bone tissue infection March 24th, 2023

News and information

Optical switching at record speeds opens door for ultrafast, light-based electronics and computers: March 24th, 2023

Robot caterpillar demonstrates new approach to locomotion for soft robotics March 24th, 2023

Semiconductor lattice marries electrons and magnetic moments March 24th, 2023

Light meets deep learning: computing fast enough for next-gen AI March 24th, 2023

Possible Futures

New experiment translates quantum information between technologies in an important step for the quantum internet March 24th, 2023

Graphene grows – and we can see it March 24th, 2023

HKUMed invents a novel two-dimensional (2D) ultrasound-responsive antibacterial nano-sheets to effectively address bone tissue infection March 24th, 2023

A universal HCl-assistant powder-to-powder strategy for preparing lead-free perovskites March 24th, 2023

Chip Technology

Graphene grows – and we can see it March 24th, 2023

Optical switching at record speeds opens door for ultrafast, light-based electronics and computers: March 24th, 2023

Semiconductor lattice marries electrons and magnetic moments March 24th, 2023

Light meets deep learning: computing fast enough for next-gen AI March 24th, 2023

Nanotubes/Buckyballs/Fullerenes/Nanorods

TUS researchers propose a simple, inexpensive approach to fabricating carbon nanotube wiring on plastic films: The proposed method produces wiring suitable for developing all-carbon devices, including flexible sensors and energy conversion and storage devices March 3rd, 2023

Current and Future Developments in Nanomaterials and Carbon Nanotubes: Applications of Nanomaterials in Energy Storage and Electronics October 28th, 2022

Strain-sensing smart skin ready to deploy: Nanotube-embedded coating detects threats from wear and tear in large structures July 15th, 2022

Boron nitride nanotube fibers get real: Rice lab creates first heat-tolerant, stable fibers from wet-spinning process June 24th, 2022

Discoveries

New experiment translates quantum information between technologies in an important step for the quantum internet March 24th, 2023

Graphene grows – and we can see it March 24th, 2023

HKUMed invents a novel two-dimensional (2D) ultrasound-responsive antibacterial nano-sheets to effectively address bone tissue infection March 24th, 2023

A universal HCl-assistant powder-to-powder strategy for preparing lead-free perovskites March 24th, 2023

Announcements

Robot caterpillar demonstrates new approach to locomotion for soft robotics March 24th, 2023

Semiconductor lattice marries electrons and magnetic moments March 24th, 2023

Light meets deep learning: computing fast enough for next-gen AI March 24th, 2023

Bilayer PET/PVDF substrate-reinforced solid polymer electrolyte improves solid-state lithium metal battery performance March 24th, 2023

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

HKUMed invents a novel two-dimensional (2D) ultrasound-responsive antibacterial nano-sheets to effectively address bone tissue infection March 24th, 2023

A universal HCl-assistant powder-to-powder strategy for preparing lead-free perovskites March 24th, 2023

Optical switching at record speeds opens door for ultrafast, light-based electronics and computers: March 24th, 2023

Robot caterpillar demonstrates new approach to locomotion for soft robotics March 24th, 2023

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project