Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Magic Trick with Gold and Glass

Abstract:
Glasses doped with gold particles of controllable size and shape deliver new materials for optoelectronic applications

Magic Trick with Gold and Glass

November 07, 2005

Even the ancient Romans were familiar with processes for coloring glass by adding gold. Initially colorless, the glass takes on a ruby-red color when heated in a controlled fashion. The source of this color is finely divided gold clusters. The light absorption depends on the concerted oscillation of the conducting electrons in all of the gold atoms in the cluster, called plasmon oscillation. Variation of the size, shape, or electrical properties of the particles’ surroundings should influence the frequency of the oscillation and thus the color of the absorbed light. This could allow for the production of materials that are suitable for use in nanophotonic components, including tiny optoelectronic circuits or optical storage devices.

How to make this work has been questionable until now, as the chemistry of gold in glass has long been a mystery. Newly published investigations have allowed K. Rademann and M. Eichelbaum in collaboration with the German Federal Institute for Materials Research and Testing to unravel this secret a little. Their first step was to produce soda–lime–silica glasses containing gold trichloride. They irradiated these glasses for five minutes with synchrotron radiation. Synchrotron radiation is extremely energetic, high-intensity light; it is produced when electrons are strongly accelerated—they nearly reach light speed within the synchrotron—and then are deflected by a magnet.

The synchrotron radiation effected a photochemical reduction of the trivalent gold ions to elemental gold, producing an even brown tone in the irradiated areas of the glasses. These were then heated to over 550 °C for a longer time (30–45 minutes) which led to the development of the red color that is characteristic of plasmon oscillation—evidence for the aggregation of gold clusters with a radius of between 3 and 6 nm, depending on the length of the treatment and the temperature. As the size of the gold particles increases, the researchers observe a red shift of the plasmon oscillation; that is, a shift to higher wavelength regions of the spectrum.

Simple heating thus allows the control of the size of gold particles in glasses that were previously activated with light; this allows for control of the absorption wavelength of the plasmon oscillation. This is a requirement for the use of these glasses as nanoscale components of optoelectronic circuits.

####


Author: Klaus Rademann, Humboldt-Universität zu Berlin (Germany),
www.chemie.hu-berlin.de/agrad/index.html

Title: On the Chemistry of Gold in Silicate Glasses: Studies on a Nonthermally Activated Growth of Gold Nanoparticles

Angewandte Chemie International Edition, doi: 10.1002/anie.200502174

Contact:
Editorial office:
angewandte@wiley-vch.de

or David Greenberg (US)
dgreenbe@wiley.com

or Julia Lampam (UK)
jlampam@wiley.co.uk

Copyright © Angewandte Chemie

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 News Press

Possible Futures

Air Force’s 30-year plan seeks 'strategic agility' August 1st, 2014

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Materials/Metamaterials

International Conference in Nanomaterials and Technologies CNT 2014 August 1st, 2014

Light pulses control graphene's electrical behavior: Finding could allow ultrafast switching of conduction, and possibly lead to new broadband light sensors August 1st, 2014

Industrial Nanotech, Inc. to Publish PCAOB Audited Financials July 31st, 2014

Carnegie Mellon Chemists Create Nanofibers Using Unprecedented New Method July 31st, 2014

Announcements

Light pulses control graphene's electrical behavior: Finding could allow ultrafast switching of conduction, and possibly lead to new broadband light sensors August 1st, 2014

President Obama Meets U.S. Laureates of 2014 Kavli Prizes August 1st, 2014

Stanford researchers seek 'Holy Grail' in battery design: Pure lithium anode closer to reality with development of protective layer of interconnected carbon domes August 1st, 2014

Air Force’s 30-year plan seeks 'strategic agility' August 1st, 2014

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE