Nanoparticle Devices Aim of Global Project
LEICESTER, England, June 21, 2006 -- Nanospin, a European Union-funded project involving information that can be stored on nanoparticles, will draw on the resources of international partners: the Universities of Leicester, Reading and Surrey (UK), the Greek National Centre for Scientific Research "Demokritos" (Athens), Sumy State University (Ukraine), the Italian National Research Council (CNR-ISM) in Rome, Universitat de Barcelona (Spain) and NT-MDT Co., Zelenograd (Russian Federation).
The scientific objective of Nanospin is to manufacturing and study the behavior of complex magnetic nanoparticles composed of a metallic core and one or more shells of ferromagnetic or antiferromagnetic metals in order to control their magnetic properties (blocking temperature, anisotropy, exchange bias, spin quantum barrier height, etc.). These so-called nano-onions have far-ranging applications in medical nanotechnology, magnetic recording and quantum devices, the University of Leicester said in a statement.
Nanospin's technological objectives are to functionalize the nanoclusters to enable them to be produced as ordered arrays on surfaces and to demonstrate proof of principle in classical and quantum single-particle data storage, the university said.
Photo: University of Leicester
It said the multiple-shell clusters will be produced by metal condensation in superfluid liquid helium (He) droplets. Large He droplets, formed by expansion of liquid helium into vacuum via a pinhole nozzle, are skimmed to form a collimated beam and pass through pickup cells where they acquire evaporated metal atoms. The atoms move through the droplet, coagulate to form clusters and cool to an ultralow temperature on a submicrosecond timescale. In contrast, the journey time between each pickup cell is milliseconds, so shell formation in one cell is complete before the droplet reaches the next cell. This will allow discrete shell structures to form sequentially.
"The project addresses an increasingly important aspect of nanotechnology: how to functionalize the properties of the individual building blocks," according to the statement. "The degree of control possible with the proposeed production technique and the ability to add extra shells of ferromagnetic and antiferromagnetic materials would enable, in principle, the design of the internal spin configuration of an individual nanocluster."
Adding a final nonmagnetic shell will promote the ordering of arrays of the functionalized nanoclusters on surfaces, the university said.
"This degree of control will have an enormous impact on technological areas of spintronics and magnetic storage such as ultrahigh density magnetic recording media and quantum computing," it added.
A simple example is a magnetic nanoparticle that can store a single data bit of information by defining the direction of its magnetization. The data storage density of modern computer disks is impressive, but if it becomes possible to store each data bit on a single nanoparticle, then storage densities 100 times greater could be achieved.
"To put this into context, such a nanoparticle medium could store about 2 million books, or a large library, on an area the size of a postage stamp," said Chris Binns, a professor of nanoscience in the physics and astronomy department at the university. "Nanotechnology -- that is, the use of structures whose dimensions are on the nanometre scale to build new materials and devices -- appears to hold the key to future developments in a wide range of technologies, including materials, science, information technology and health care.
"An important aspect of nanotechnology is the recognition that sufficiently small pieces of matter (nanoparticles) have electronic magnetic and optical properties that are different from the bulk material," Binns said. "In addition, their properties are size-dependent, so nanoparticles can be considered as new building blocks of matter, or 'giant atoms,' whose properties can be tailored."
For more information, visit: www.le.ac.uk
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