Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Purdue’s self-assembled ’nanorings’ could boost computer memory


Shown are cobalt nanoparticles that have self-assembled into bracelet-like "nanorings." The rings’ magnetic flux can be oriented in one of two directions – clockwise or counterclockwise – a characteristic that could represent binary numbers in magnetic memory devices. Because the flux direction remains even without a constant power supply, it is possible these rings could lead to so-called "non-volatile" computer memory, which would not be wiped out in the event of a system failure. (Graphic/VCH Publishers)

Recent nanotechnology research at Purdue University could pave the way toward faster computer memories and higher density magnetic data storage, all with an affordable price tag.

Just like the electronics industry, the data storage industry is on the move toward nanoscale. By shrinking components to below 1/10,000th the width of a human hair, manufacturers could make faster computer chips with more firepower per square inch. However, the technology for making devices in that size range is still being developed, and the smaller the components get, the more expensive they are to produce.

Purdue chemist Alexander Wei may have come up with a surprisingly simple and cheap solution to the shrinking data storage problem. Wei’s research team has found a way to create tiny magnetic rings from particles made of cobalt. The rings are much less than 100 nanometers across – an important threshold for the size-conscious computer industry – and can store magnetic information at room temperature. Best of all, these "nanorings" form all on their own, a process commonly known as self-assembly.

"The cobalt nanoparticles which form the rings are essentially tiny magnets with a north and south pole, just like the magnets you played with as a kid," said Wei, who is an associate professor of chemistry in Purdue’s School of Science. "The nanoparticles link up when they are brought close together. Normally you might expect these to form chains, but under the right conditions, the particles will assemble into rings instead."

The research appeared as a "Very Important Paper" in the November issue of the chemistry journal Angewandte Chemie. Wei collaborated with lead author Steven Tripp and Rafal Dunin-Borkowski, an electron microscopist at the University of Cambridge.

The magnetic dipoles responsible for nanoring formation also produce a collective magnetic state known as flux closure. There is strong magnetic force, or flux, within the rings themselves, stemming from the magnetic poles each particle possesses. But after the particles form rings, the net magnetic effect is zero outside. Tripp developed conditions leading to the self-assembly of the cobalt nanorings, then initiated a collaboration with Dunin-Borkowski to study their magnetic properties. By using a technique known as electron holography, the researchers were able to observe directly the flux-closure states, which are stable at room temperature.

"Magnetic rings are currently being considered as memory elements in devices for long-term data storage and magnetic random-access memory," Wei said. "The rings contain a magnetic field, or flux, which can flow in one of two directions, clockwise or counterclockwise. Magnetic rings can thus store binary information, and unlike most magnets, the rings keep the flux to themselves. This minimizes crosstalk and reduces error during data processing."

When you turn on your computer, it loads its operating system and whatever documents you are working on into its RAM, or random-access memory. RAM is fast, enabling your computer to make quick changes to whatever is stored there, but its chief drawback is its volatility – it cannot perform without a continuous supply of electricity. Many people have experienced the frustration of losing an unsaved document when their computer suddenly crashes or loses power, causing all the data stored in RAM to vanish.

"Nonvolatile memory based on nanorings could in theory be developed," Wei said. " For the moment, the nanorings are simply a promising development."

Preliminary studies have shown that the nanorings’ magnetic states can be switched by applying a magnetic field, which could be used to switch a nanoring "bit" back and forth between 1 and 0. But according to Wei, perhaps the greatest potential for his group’s findings lay in the possibility of combining nanorings with other nanoscale structures.

"Integrating the cobalt nanorings with electrically conductive nanowires, which can produce highly localized magnetic fields for switching flux closure states, is highly appealing." he said. "Such integration may be possible by virtue of self-assembly."

Several research groups have created magnetic rings before but have relied on a "top-down" manufacturing approach, which imposes serious limitations on size reduction.

"The fact that cobalt nanoparticles can spontaneously assemble into rings with stable magnetic properties at room temperature is really remarkable," Wei said. "While this discovery will not make nonvolatile computer memory available tomorrow, it could be an important step towards its eventual development. Systems like this could be what the data storage industry is looking for."

Wei’s group is associated with the Birck Nanotechnology Center, which will be one of the largest university facilities in the nation dedicated to nanotechnology research when construction is completed in 2005. Nearly 100 groups associated with the center are pursuing research topics such as nanometer-sized machines, advanced materials for nanoelectronics and nanoscale biosensors.

Funding for Wei’s research was provided in part by the National Science Foundation and the Department of Defense.

Writer: Chad Boutin, (765) 494-2081,
Source: Alexander Wei, (765) 494-5257,
Purdue News Service: (765) 494-2096;

Chad Boutin | Purdue News
Further information:

More articles from Information Technology:

nachricht Fraunhofer FIT joins Facebook's Telecom Infra Project
25.10.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Stanford researchers create new special-purpose computer that may someday save us billions
21.10.2016 | Stanford 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: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Prototype device for measuring graphene-based electromagnetic radiation created

28.10.2016 | Power and Electrical Engineering

Gamma ray camera offers new view on ultra-high energy electrons in plasma

28.10.2016 | Physics and Astronomy

When fat cells change their colour

28.10.2016 | Life Sciences

More VideoLinks >>>