Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Nano-hillocks: Of mountains and craters

Following bombardment with highly charged ions, nano-hillocks have formed in an area of localized melting. Atomic force microscope image.
Picture: HZDR
Following bombardment with highly charged ions, nano-hillocks have formed in an area of localized melting. Atomic force microscope image.

Picture: HZDR

Abstract:
n the field of nanotechnology, electrically-charged particles are frequently used as tools for surface modification. Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the TU Vienna were at last able to reconcile important issues concerning the effects of highly charged ions on surfaces.

Nano-hillocks: Of mountains and craters

Dresden, Germany | Posted on October 1st, 2012

Ion beams have been used for some time now for surface modification as ions are capable of carrying such high energies that a single particle alone can induce drastic changes to the surface under bombardment. Following careful examination, an international team of researchers was at last able to shed light on the reasons why sometimes craters and other times hillocks are forming as a result of this process. Their findings have recently been published in the scientific journal, Physical Review Letters.
Charge instead of speed

"If the goal is to deposit a maximum amount of energy on a tiny spot on the surface, it is of comparatively little use to simply bombard the surface with fast atoms," explains Prof. Friedrich Aumayr of the TU Vienna's Institute of Applied Physics. "Fast particles penetrate deep into the material thereby depositing their energy over a wide range." If, however, you first strip a large number of electrons from individual atoms and then allow these highly charged ions to collide with the material surface, the effects you get are quite dramatic as the energy that was previously required to ionize the atoms is now being released within a very small area of a few nanometers in diameter, and within an ultrashort time.

This can lead to melting of a very small volume of the material, loss of its orderly atomic structure, and, finally, its expansion. The large number of electronic excitations that result from the ion's interactions with the surface has a strong impact on the material and ultimately leads to the atoms being bumped out of position. The end-result is nano-hillock formation - the appearance of tiny protrusions on the material's surface. If the energy required to initiate melting of the material is insufficient, small holes or defects will form on or below the surface instead.

Elaborate experiments at the HZDR facility for highly charged ions were just as important to obtaining a detailed picture of the processes that take place at the material's surface as were computer simulations and extensive theoretical work. "At our new HZDR facility, we have the capabilities for deliberately forming nano-hillocks and nano-craters on surfaces. In close collaboration with the groups of our colleagues Friedrich Aumayr and Joachim Burgdörfer at the TU Vienna we succeeded to grasp the underlying physical mechanisms in more detail", explains Dr. Stefan Facsko. Egyptian physicist Dr. Ayman El-Said, who spent two years as a Humboldt Foundation fellow conducting research at HZDR, made substantial contributions to the current body of research in this field.
Assumptions confirmed

The scientists are calling their results the missing important piece of the puzzle to help them understand the interaction of highly charged ions with surfaces. By subjecting the sample to an acid treatment following ion bombardment, they are able to document the extent to which a surface is modified at given energies. The formation of nano-hillocks depends to a large extent on the ion beams' charge state and to a lesser extent on their velocity. The formation of craters, on the other hand, is dependent upon both the charge state and the kinetic energy of the ions. The Vienna and Dresden researchers had long suspected this and were now at last able to produce the necessary evidence obtained from their experiments conducted at the HZDR.

####

For more information, please click here

Contacts:
Dr. René Heller
Institute of Ion Beam Physics and Materials Research at HZDR
Phone: +49 351 260-3617


Dr. Christine Bohnet
Press Officer

49-351-260-2450
oder +49 160 969 288 56

Copyright © Helmholtz Association of German Research Centres

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

Publication

Related News Press

News and information

Graphene chips are close to significant commercialization October 1st, 2014

Production of Filters for Separation of Water from Petroleum Products in Iran October 1st, 2014

Yale University and Leica Microsystems Partner to Establish Microscopy Center of Excellence: Yale Welcomes Scientists to Participate in Core Facility Opening and Super- Resolution Workshops October 20 Through 31, 2014 September 30th, 2014

Speed at its limits September 30th, 2014

Physics

Brookhaven Lab's National Synchrotron Light Source II Approved to Start Routine Operations: Milestone marks transition to exciting new chapter September 23rd, 2014

Toward optical chips: A promising light source for optoelectronic chips can be tuned to different frequencies September 19th, 2014

Elusive Quantum Transformations Found Near Absolute Zero: Brookhaven Lab and Stony Brook University researchers measured the quantum fluctuations behind a novel magnetic material's ultra-cold ferromagnetic phase transition September 15th, 2014

Excitonic Dark States Shed Light on TMDC Atomic Layers: Berkeley Lab Discovery Holds Promise for Nanoelectronic and Photonic Applications September 11th, 2014

Discoveries

Production of Filters for Separation of Water from Petroleum Products in Iran October 1st, 2014

Speed at its limits September 30th, 2014

Research mimics brain cells to boost memory power September 30th, 2014

Ad-REIC vaccine: A magic bullet for cancer treatment September 30th, 2014

Announcements

Graphene chips are close to significant commercialization October 1st, 2014

Production of Filters for Separation of Water from Petroleum Products in Iran October 1st, 2014

New Topical Hemostatic Agent: Neutral Self-Assembling Peptide Hydrogel September 30th, 2014

Chemical interactions between silver nanoparticles and thiols: A comparison of mercaptohexanol again September 30th, 2014

Tools

Yale University and Leica Microsystems Partner to Establish Microscopy Center of Excellence: Yale Welcomes Scientists to Participate in Core Facility Opening and Super- Resolution Workshops October 20 Through 31, 2014 September 30th, 2014

Park Systems Announces Outsourced Analytical Services Including AFM Surface Imaging, Data Analysis and Interpretation September 30th, 2014

Iranian Scientists Determine Grain Size, Minimize Time of Nanocomposite Synthesis September 29th, 2014

Oxford Instruments launches 3rd annual Indian nanotechnology seminars in Kolkata and Delhi - sharing expertise with Nanotechnology researchers in India September 25th, 2014

Research partnerships

Research mimics brain cells to boost memory power September 30th, 2014

'Pixel' engineered electronics have growth potential: Rice, Oak Ridge, Vanderbilt, Penn scientists lead creation of atom-scale semiconducting composites September 29th, 2014

Teijin Aramid’s carbon nanotube fibers awarded with Paul Schlack prize: New generation super fibers bring wave of innovations to fiber market September 25th, 2014

Smallest-possible diamonds form ultra-thin nanothread September 25th, 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