A group of London-based scientists at the London Centre for Nanotechnology along with a team of researchers from the Universities if Cambridge and Oxford have discovered a process by which to utilize the Third Law of Thermodynamics and renew it within thin films of a magnetic material called spin ice.
Research has determined that thin films of spin ice contain highly practical properties could aid in the furthering of applications of the magnetic mirror of electricity which scientists named “magnetricity”. Previous studies have also established that there’s a limit to just how cold something can get. That limit is reported to be minus 273 degrees centigrade or “absolute zero”.
This is founded on the Third Law of Thermodynamics which is the general notion that absolute zero is equivalent to zero entropy. There is one exception to this law and that is spin ice. Again, at absolute zero, the entropy of any substance, defined as the measure of randomness of the atoms within it, should be zero.
When it comes to spin ice however, the atomic magnetic moments reportedly remain in the drop to absolute zero. For the first time, these scientists have produced a thin spin ice film. It’s only a few nanometers thick.
Professor Steve Bramwell of UCL Department of Physics and Astronomy noted: “Restoration of the Third Law in spin ice thin films adds an unexpected twist to the story of spin ice. How the Third Law (of Thermodynamics) is first violated and then restored in spin ice is an interesting question of basic physics”.
Doctor Laura Bovo of the UCL London Centre for Nanotechnology and leading author of the scientific team’s research paper stated: “This result shows that we can use strain to drastically alter and control the spin ice state. It opens up new possibilities for the control and manipulation of magnetricity and magnetic monopoles in spin ice.” They added that this scientific revelation can aid in the use of spin ice in magnetic technology such as that found in computer hard disks which are generally built on thin magnetic films.
(Image courtesy of L. Bovo/UCL)