Washington DC (SPX) Oct 27, 2010
Just as landscape photographs shot in low-angle light dramatically accentuate subtle swales and mounds, depositing metal vapors at glancing angles turns a rough surface into amazing nanostructures with a vast range of potential properties.
For decades, vapor deposition has been a standard technique for creating modern microelectronic circuits. But nearly all of industry's efforts have been devoted to making structures as flat and smooth as possible.
Rather than placing metal sources in the high-noon position used to make featureless structures, Daniel Gall of Rensselaer Polytechnic Institute is one of several dozen research leaders who place them at very narrow angles akin to sunrise or sunset illumination.
Metal atoms then hit primarily any high spots on the target surface. Continued deposition creates a forest of nanorods, rather than flat films, since each growing rod shadows a volume behind it. Starting with a patterned substrate yields a regular array of nanoscale columns, like skyscrapers in downtown Manhattan.
Gall describes his research at the AVS 57th International Symposium and Exhibition, which took place last week at the Albuquerque Convention Center in New Mexico.
In his talk, Gall reveals a new theory that predicts how the deposition temperature and diffusion affects the diameters of the nanorods.
"Atoms moving by surface diffusion typically smooth the surface," Gall says. "Atomic shadowing causes the opposite effects, making the surface rough. Glancing-angle deposition extends shadowing effects to higher temperatures, which lead to larger-diameter nanorods."
He also illustrates his presentation with images of a variety of nanostructures created in his lab, including curiously shaped half-moons made when he started with a pattern of self-assembled spheres.
Future applications for nanorod structures such as Gall's include nanosensors, optical elements, fuel-cell cathodes and electrical contacts for buffering thermal expansion.
Share This Article With Planet Earth
American Institute of Physics
Nano Technology News From SpaceMart.com
Computer Chip Architecture, Technology and Manufacture
Nanotube Thermopower Offers Promise
Washington DC (SPX) Oct 27, 2010
When weighing options for energy storage, different factors can be important, such as energy density or power density, depending on the circumstances. Generally batteries - which store energy by separating chemicals - are better for delivering lots of energy, while capacitors - which store energy by separating electrical charges - are better for delivering lots of power (energy per time). It wou ... read more
Boeing Ships LightSquared's SkyTerra One Mobile ComSat To Launch Site|
Hylas-1 Satellite Readied For Launch From European Spaceport
ILS Proton Successfully Launches XM-5 Satellite
Ariane Moves Into Final Phase Of Globalstar Soyuz 2 Launch Campaign
2013 Earliest Launch Date For China Mars Mission
A One-Way Trip To Mars Would Be Affordable
Curiosity Builds A New Mars Rover
Opportunity's Eastward View After Sol 2382 Drive
NASA Awards Contract To Team FREDNET Google Lunar X PRIZE Contender
Collision Spills New Moon Secrets
LRO Detects Surprising Gases In LCROSS Lunar Impact Plume
Moon's 'treasure chest' includes silver : study
Reaching The Mid-Mission Milestone On The Way To Pluto
New Horizons Student Dust Counter Instrument Breaks Distance Record
Nitrogen Methane Dominate Icy Surface Of Eris
The Longest Space Mission
Planets Discovered Around Elderly Binary Star
Astronomers Find Weird, Warm Spot On An Exoplanet
New techniqe aiding planet searches
Planet Hunters No Longer Blinded By The Light
Commercial spacecraft launch test delayed
DLR Launches 'STERN' Rocket Programme For Students
U.K. predicts 'spaceplane' in 10 years
NASA chief says pleased with 'comprehensive' China visit
The International Future In Space
International Crews for Shenzhou
China Eyes Extended Mission Beyond Moon
Contract Signing Gives Galileo System Its Operators
Countdown To Comet Flyby Down To Nine Days
New Cometary Phenomenon Greets Approaching Spacecraft
When Is A Comet Not A Comet
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal 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. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement|