PSI researchers
have created a magnetic metamaterial made of long nanomagnets,
arranged in a
flat, honeycomb pattern. The arrangement of magnetisation in the synthetic
material assumed
very different states at different temperatures – just like molecules in ice
are more ordered
than in water, and are in turn more ordered in water than in steam.
(Image: PSI/Luca
Anghinolfi)
(September 22, 2015) Researchers
at the Paul Scherrer Institute (PSI) created a synthetic material out of 1
billion tiny magnets. Astonishingly, it now appears that the magnetic
properties of this so-called metamaterial change with the temperature, so that
it can take on different states; just like water has a gaseous, liquid and a
solid state. This material made of nanomagnets might well be refined for
electronic applications of the future – such as for more efficient information
transfer.
A synthetic material – created from 1 billion nanomagnets –
assumes different aggregate states depending on the temperature: the so-called
metamaterial exhibits phase transitions, much like those between steam, water
and ice. This effect was observed by a team of researchers headed by Laura
Heyderman from PSI. “We were surprised and excited,” explains Heyderman. “Only
complex systems are able to display phase transitions.” And as complex systems
can provide new kinds of information transfer, the result of the new study also
reveals that the PSI researchers’ metamaterial would be a potential candidate
here.
The major advantage of the synthetic metamaterial is that it
can be customised virtually freely. While the individual atoms in a natural
material cannot be rearranged with pinpoint precision on such a grand scale,
the researchers say that this is possible with the nanomagnets.
Honeycomb of
nanomagnets
The magnets are only 63 nanometres long and shaped roughly
like grains of rice. The researchers used a highly advanced technique to place 1
billion of these tiny grains on a flat substrate to form a large-scale
honeycomb pattern. The nanomagnets covered a total area of five by five
millimetres.