Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineered materials: Custom-made magnets

24.05.2012
A novel approach to designing artificial materials could enable magnetic devices with a wider range of properties than those now available. An international team of researchers have now extended the properties and potential uses of metamaterials by using not one but two very different classes of nanostructures, or metamolecules.

The properties of a substance are largely dependent on its constituent atoms and the way that these atoms interact with each other. The finite number of atom types, however, imposes a limit on the range of properties that a conventional material can have.


An array of metamolecules comprising silicon spheres and copper split-rings can be used to control magnetization waves.
Copyright : © 2012 American Chemical Society

In contrast, a new class of engineered materials called metamaterials have no such limitation. Metamaterials are typically composed of an array of nanostructures that can interact with electromagnetic waves in much the same way as atoms. In addition, the optical properties of these metamaterials can be tuned by altering the size and shape of nanostructures.

An international team of researchers led by Boris Luk'yanchuk at the A*STAR Data Storage Institute have now extended the properties and potential uses of metamaterials by using not one but two very different classes of nanostructures, or metamolecules.

Luk'yanchuk and the team mathematically modelled a two-dimensional array of metamolecules comprising a silicon sphere next to a partially incomplete copper ring. They studied the influence of both the sphere and the split ring on the magnetic component of an incident electromagnetic wave — a property known as magnetization.

"When the two structures were more than one micrometer apart, they both acted to increase the local magnetic field," says Luk’yanchuk. However, they started to interact when moved closer together, and the researchers observed that the magnetization of the split ring decreases and even becomes negative for separations smaller than 0.5 micrometers.

This situation is somewhat analogous to the magnetic ordering in ‘natural’ materials. When all the atoms contribute in a positive way to a material’s magnetic properties, the material becomes a ferromagnet. However, when alternating regions of the material have opposite magnetization, the material is said to be antiferromagnetic.

"We demonstrate that our hybrid lattices of metamolecule exhibit distance-dependent magnetic interaction, opening new ways for manipulating artificial antiferromagnetism with low-loss materials," explains Luk'yanchuk.

Although the analogy between metamaterials and magnetic materials is not a perfect one, most metamaterials are said to be ferromagnet-like. The design proposed by Luk'yanchuk and the team closely mimics antiferromagnetic ordering, and this opens an opportunity for researchers to study antiferromagnetic phenomena in metamaterials. One notable example is giant magnetoresistance, a phenomenon that is at the heart of modern electronic memories.

Luk'yanchuk affirms that a metamaterial analog would offer exciting research prospects. "We believe that our work has the potential to make a strong impact towards the development of on-chip integrated solutions for reconfigurable and optically-controlled metamaterials."

The A*STAR-affiliated researchers contributing to this research are from the Data Storage Institute.

References:

Miroshnichenko, A. E., Luk'yanchuk, B., Maier, S. A. & Kivshar, Y. S. Optically induced interaction of magnetic moments in hybrid metamaterials. ACS Nano 6, 837–842 (2012).

Lee Swee Heng | Research asia research news
Further information:
http://www.a-star.edu.sg
http://www.researchsea.com

More articles from Materials Sciences:

nachricht ADIR Project: Lasers Recover Valuable Materials
21.07.2017 | Fraunhofer-Institut für Lasertechnik ILT

nachricht High-tech sensing illuminates concrete stress testing
20.07.2017 | University of Leeds

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>