London, June 27 (ANI): A team of researchers led by a scientist of Indian origin has created new 'superatoms' with magnetic properties for the first time, a breakthrough that could be used to make "spintronic devices", faster computer processors and denser memory storage.
According to a report in New Scientist, the research was led by Shiv Khanna from Virginia Commonwealth University.
Superatoms were discovered in the 1980s when Walter Knight and colleagues at the University of California, Berkeley, found that groups of sodium atoms can share electrons amongst themselves.
The electrons form a collective "supershell" that coats the cluster.
Until now, clusters that copy the magnetic properties of other elements have proved more difficult to design.
Magnetism is caused by the spin of an atom's electrons, which are arranged in shells, or orbitals, around the atom's nucleus.
Their net spin determines the strength of the atom's magnetic "moment," and because they tend to occur in pairs that cancel each other out, it is the atom's unpaired electrons that contribute to its magnetic moment.
Unpaired electrons, however, will make an atom, or a superatom, more likely to react with others in an attempt to fill its orbitals and become stable.
As a result, stability and magnetism have long been thought to be mutually exclusive.
A team led by Shiv Khanna at Virginia Commonwealth University has come up with a way around the problem.
Khanna's team worked out that encapsulating an atom of vanadium in a cage of eight caesium atoms would create a stable supershell of electrons around the entire cluster.
This would prevent the vanadium atom's unpaired electrons from reacting with other atoms, maintaining its magnetism.
The arrangement would yield a magnetic moment of five Bohr magnetons, which is the same as an atom of manganese.
"What we have done is expand the range of possible magnetic materials," said Khanna.
Khanna's magnetic superatoms are only calculations at this point, but he has funding from the Department of Energy to make them a reality.
He hopes the clusters can be used to give researchers a new dimension of control in designing new materials.
For example, stable magnetic clusters could one day be used in new "spintronic" devices, which compute or store information using magnetic moments rather than simply electrical charge.
Encoding data in this way means the devices can be far smaller than those used to make conventional electronic components, potentially providing an overall boost in computing power. (ANI)