Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

What makes nanowires so attractive

14.07.2009
Chinese-German team clearly identifies semiconducting nanowires with intrinsic ferromagnetic characteristics / Publication comes out today in "Nature Nanotechnology"

For a Chinese-German research team the "force of attraction" of minute nanowires is not only based on their special scientific interests: Physicists of the Chinese University of Hongkong and the Friedrich Schiller University Jena were able to prove for the first time that cobalt doped nanowires made from zinc oxide have intrinsic ferromagnetic characteristics - and therefore in principle work like tiny bar magnets.

The scientists around Prof. Dr. Quan Li (Hong Kong) and Prof. Dr. Carsten Ronning (Jena) will publish the results of their research in the current online edition of the well renowned journal "Nature Nanotechnology".

For that Prof. Ronning and his Jena team used their know-how about the preparation of semiconductor nanostructures and their optical characteristics, and doped zinc oxide wires. These were then examined for their magnetic properties by the Chinese colleagues around Prof. Li - an acknowledged expert in the field of electron microscopy. The innovative combination of two analytical methods - transmission electron microscopy and electron magnetic chiral dichroism - is responsible for the surprising outcome. "We realized that cobalt doping gives intrinsic ferromagnetic properties while iron does not", comments Prof. Li. Further investigations must now clarify where these differences come from.

The production of magnetic semiconducting nanowires has so far been basic research, as Quan Li emphasizes. But medium term "we might be able to help push open the door to spintronics". "Spintronics" is a new field in semiconductor physics: While traditional semiconductor electronics is based on the electrons' electrical charge, spintronics additionally uses the spin, the angular momentum, of the electrons. "That momentum can occur in two directions resulting in a magnetic moment", explains Prof. Ronning.

This new development could bring real advantages: Common electronic components need 10.000 to 100.000 electrons for a single switching action. Semiconductor components switching only the spin of electrons need only one electron to transport the necessary information. "That means that spintronic semiconductors could switch much faster than common electronic components", says Quan Li. Furthermore they would need only a fraction of the energy.

The precondition for a further development of spintronics however is, that semiconductors with intrinsic ferromagnetic characteristics can be produced at all. Intense worldwide research has been conducted for about a decade - so far with moderate success: There has not been a method clearly proving intrinsic ferromagnetism so far. Thanks to the current results the physicists have taken the field an important step further.

The original publication Z. H. Zhang, Xuefeng Wang, J. B. Xu, S. Muller, C. Ronning & Quan Li. Evidence of intrinsic ferromagnetism in individual dilute magnetic semiconducting nanostructures can be found under: http://www.nature.com/doifinder/10.1038/nnano.2009.181

Contact:
Prof. Dr. Quan Li
Department of Physics, The Chinese University of Hong Kong
Phone: + (852) 2609 6323
Email: liquan[at]phy.cuhk.edu.hk
http://www.phy.cuhk.edu.hk/qli/
Prof. Dr. Carsten Ronning
Institute for Solid State Physics, Friedrich Schiller University Jena
Phone: + (49) 3641 947300
Email: carsten.ronning[at]uni-jena.de
http://www.nano.uni-jena.de/en

Dr. Ute Schönfelder | idw
Further information:
http://www.nano.uni-jena.de/en
http://www.phy.cuhk.edu.hk/qli/
http://www.nature.com/doifinder/10.1038/nnano.2009.181

More articles from Physics and Astronomy:

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

nachricht Magnetic moment of a single antiproton determined with greatest precision ever
19.01.2017 | Johannes Gutenberg-Universität Mainz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>