Pin It

Thin films of spin ice have been shown to demonstrate surprising properties which could help in the development of applications of magnetricity, the magnetic equivalent of electricity.

Published today in Nature Communications, a team of researchers based at the London Centre for Nanotechnology (LCN), in collaboration with scientists from Oxford and Cambridge, found that, against expectations, the Third Law of Thermodynamics could be restored in thin films of the magnetic material spin ice.

In the familiar world around us it is always possible to make things colder, but science has established that there is a limit to how cold an object can be -- the so-called `absolute zero' of temperature, or minus 273 degrees centigrade.

At the absolute zero it is expected that the entropy of a substance, a measure of the randomness of the atoms within it, should itself be zero. The concept that absolute zero equates to zero entropy or randomness is called the Third Law of Thermodynamics.

A famous exception to the Third Law is spin ice, in which atomic magnetic moments or `spins' remain random in the approach to absolute zero. This randomness gives spin ice properties that more conventional materials don't have, most notably `magnetic monopoles'.

In this study, the researchers fabricated, for the first time, thin spin ice films with a thicknesses of only a few nanometres.

To read more, click here.