Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Space Industry and Business News .




TECH SPACE
Angling for gold
by Staff Writers
Heidelberg, Germany (SPX) Sep 21, 2012


Illustration only.

A study on how gold atoms bond to other atoms using a model that takes into account bonds direction has been carried out by physicist Marie Backman from the University of Helsinki, Finland, and colleagues. These findings, which are about to be published in EPJ B, are a first step toward better understanding how gold binds to other materials through strong, so-called covalent, bonds.

What scientists need is an empirical model, based on a so-called potential, that describes the gold-gold bond in a reliable way. Most previous models only accounted for interactions in the spherical electron density around the atom.

Although it is suitable to describe bonds between gold atom pairs, it is not adequate to describe how surface gold atoms bond to other materials. In such a case, the density of interacting electrons is no longer spherical.Indeed, bond angles matter when gold binds to other materials.

Thus, the authors used a model based on potentials with angular dependence, referred to as Tersoff potential. It offers a compromise between including bond directionality, which is needed for covalent bonds, and keeping the computer time needed for the simulations low. The authors used theoretical and computational analysis to study gold atoms interacting with their neighbours.

They fitted their potential functions to the most important observed characteristics of gold, such as gold atoms' lattice constant, binding energy and elastic constants. Thanks to such potential functions they were then able to describe bonding in atomistic simulations.

This involves, first, determining the forces on each atom based on their relative positions and second solving equations of motion, to show how the atoms move, on a very short time scale.Building on this model, future work could, for example, involve the development of cross potentials for gold nanoparticles and nanorods in a matrix, typically used in biomedical imaging and nanophotonics.

M. Backman, N. Juslin, and K. Nordlund, Bond order potential for gold, European Physical Journal B 85:317, DOI 10.1140/epjb/e2012-30429-y

.


Related Links
Springer Publication
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
New NIST screening method identifies 1,200 candidate refrigerants to combat global warming
Washington DC (SPX) Sep 21, 2012
Researchers at the National Institute of Standards and Technology (NIST) have developed a new computational method for identifying candidate refrigerant fluids with low "global warming potential" (GWP) - the tendency to trap heat in the atmosphere for many decades - as well as other desirable performance and safety features. The NIST effort is the most extensive systematic search for a new ... read more


TECH SPACE
iPhone 5 rollout draws big crowds worldwide

Using a laser to 'see' the smallest world

YouTube seeking education video 'gurus'

Angling for gold

TECH SPACE
Hughes Awarded Custom SATCOM Solutions Contract by GSA

4 SOPS begins testing newest AEHF satellite

SES Government Solutions Awarded Custom Satellite Solutions Contract in the US

Boeing Chosen for US Government's COMSATCOM Services Acquisition Program

TECH SPACE
Fueling underway with the Galileo satellites for next Soyuz launch from French Guiana

SpaceX, NASA Target Oct. 7 Launch For Resupply Mission To Space Station

Failure Review Oversight Board Establishes Proton Return to Flight Schedule

HISPASAT chooses Arianespace to launch its Amazonas 4A and AG1 satellites

TECH SPACE
China launches another 2 navigation system satellites

Improved positioning indoors

ITT Exelis announces new capability in GPS interference, detection and geolocation

Countdown: a month to go to Galileo's next launch

TECH SPACE
Indian air force to buy French fighters

Japan's ANA says to order 11 more Dreamliners

New airport system facilitates smoother take-offs and landings

US selling Indonesia eight Apache helicopters

TECH SPACE
Single-atom writer a landmark for quantum computing

Supercomputer breakthrough for Australian team

Radiation-Enabled Computer Chips Could Lead to Low-Cost Security Imaging Systems

Memristors based on transparent electronics offer technology of the future

TECH SPACE
Knight Foundation invests to accelerate data projects

First Images from SPOT 6 Satellite

Apple fans complain of missing landmarks in new map system

Pioneering UK project to improve land carbon intelligence accuracy and reliability

TECH SPACE
Measuring mercury levels: Nano-velcro detects water-borne toxic metals

Indonesian lives risked on 'world's most polluted' river

Oil spill ship's officers deported from New Zealand

Chemical use inflicts mounting bill on poor countries: UN




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. 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 Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement