Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

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

Physics

Solid state physics: Quantum matter stuck in unrest August 1st, 2015

News and information

Transparent, electrically conductive network of encapsulated silver nanowires: A novel electrode for optoelectronics August 1st, 2015

Harris & Harris Group Portfolio Company, HZO, Announces Partnerships with Dell and Motorola August 1st, 2015

Advances and Applications in Biosensing, Sensor Power, and Sensor R&D to be Covered at Sensors Global Summit August 1st, 2015

Kalam: versatility personified August 1st, 2015

Discoveries

Shaping the hilly landscapes of a semi-conductor nanoworld August 1st, 2015

Solid state physics: Quantum matter stuck in unrest August 1st, 2015

Self-assembling, biomimetic membranes may aid water filtration August 1st, 2015

Transparent, electrically conductive network of encapsulated silver nanowires: A novel electrode for optoelectronics August 1st, 2015

Announcements

Self-assembling, biomimetic membranes may aid water filtration August 1st, 2015

Transparent, electrically conductive network of encapsulated silver nanowires: A novel electrode for optoelectronics August 1st, 2015

Harris & Harris Group Portfolio Company, HZO, Announces Partnerships with Dell and Motorola August 1st, 2015

Advances and Applications in Biosensing, Sensor Power, and Sensor R&D to be Covered at Sensors Global Summit August 1st, 2015

Tools

Heating and cooling with light leads to ultrafast DNA diagnostics July 31st, 2015

Take a trip through the brain July 30th, 2015

Publication on Atomic Force Microscopy based nanoscale IR Spectroscopy (AFM-IR) persists as a 2015 top downloaded paper July 29th, 2015

Nanometrics Announces Upcoming Investor Events July 28th, 2015

Research partnerships

Newly-Developed Polymers Control Size of Nanoparticles during Production Process July 30th, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

Spintronics: Molecules stabilizing magnetism: Organic molecules fixing the magnetic orientation of a cobalt surface/ building block for a compact and low-cost storage technology/ publication in Nature Materials July 25th, 2015

Stretching the limits on conducting wires July 25th, 2015

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