Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Computer models show device size matters

14.02.2014
Simulating the magnetic properties of nanostructures could help to design electronic memories with increased storage capacity

Scientists hope that patterning magnetic materials with nanometer-scale structures will help the development of non-volatile electronic memories with large storage capacities and no moving parts. So-called magnetoresistive random access memories are one example. But material properties at such tiny dimensions are not always the same as those of larger structures.


The ‘in-plane’ ferromagnetic-resonance response of a magnetic nanostructure changes with device size —shown here in the simulation results by the rapidly varying colors. The ‘out-of-plane’ response, on the other hand, is relatively constant.

© 2014 A*STAR Data Storage Institute

Kwaku Eason, Maria Sabino and their co-workers from the A*STAR Data Storage Institute, A*STAR National Metrology Centre and National University of Singapore have now modeled the changes in the characteristics of magnetic materials as devices are reduced in size to the nanoscale1.

The researchers focused their attention on modeling a powerful and widespread tool for characterizing magnetic materials called ferromagnetic resonance (FMR). FMR measures the absorption of microwave radiation by a thin sample. Knowing which microwave frequencies are absorbed the most can provide a number of key material properties. One such crucial property is the damping parameter, which is an indicator of how quickly a memory made from the magnetic material can store and release data.

The team employed a mathematical tool, known as the finite element method, to simulate a simple cylindrical nanodevice in all three dimensions. By calculating the energy levels of the device in an external magnetic field, the team could predict the FMR signal for devices of varying sizes.

The researchers compared their simulations to experimental data obtained on nanodisks made of a nickel–iron alloy, known as permalloy, and found good agreement for all device sizes. “Other groups have provided additional experimental results that further confirm the accuracy of our predictions,” says Eason.

The ability to predict the damping parameter of nanostructured magnetic materials is important because it is difficult to experimentally measure this property — partly because FMR signals from tiny targets are usually weak. Instead, researchers must study much larger devices and hope that the damping parameter is similar for nanostructures.

Recent experiments have conflicted on this point of scale. “One research group found from their experiments that device size does not matter in the damping measurement, while another group found that it does,” explains Eason. “We have resolved this dilemma: it turns out that they were both right.” Sabino adds: “The results were contradictory because of the different material properties.”

The simulations showed that the ‘in-plane’ magnetic properties are sensitive to the dimensions of the device, whereas the ‘out-of-plane’ properties are constant (see image).

“Contributing to a clear understanding of this effect is one of the most gratifying parts of this work,” says Eason.

The A*STAR-affiliated researchers contributing to this research are from the Singapore-based Data Storage Institute and the National Metrology Centre

Journal information

Eason, K., Sabino, M. P. R. G., Tran, M. & Liew, Y. F. Origins of magnetic damping measurement variations using ferromagnetic resonance for nano-sized devices. Applied Physics Letters 102, 232405 (2013).

A*STAR Research | Research asia research news
Further information:
http://www.a-star.edu.sg
http://www.researchsea.com
http://www.research.a-star.edu.sg/research/6881

More articles from Information Technology:

nachricht Defining the backbone of future mobile internet access
21.07.2017 | IHP - Leibniz-Institut für innovative Mikroelektronik

nachricht Researchers create new technique for manipulating polarization of terahertz radiation
20.07.2017 | Brown University

All articles from Information Technology >>>

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 >>>