Researchers at the Paul Scherrer Institute (PSI) announced they have created a synthetic material with magnetic properties capable of changing states – just as water changes from solid ice to liquid or steam – with temperature change. Constructed from 1 billion tiny magnets, this new material may be the future for the world of electronics as it could facilitate information transfer.
Each magnet within the new metamaterial is shaped like a grain of rice and roughly 63 nanometers in length. Using a highly advanced technique, 1 billion of these nanomagnets were placed in a honeycomb pattern on a flat substrate. In total, the nanomagnets covered an area spanning five-by-five millimeters.
Initially, the scientists studied the material and its magnetic properties at room temperature. They observed there was no real order to the magnetic orientation, as the magnetic north and south poles of the individual grains were pointing in random directions. The researchers then gradually cooled the material and noticed that, as the temperature dropped, the magnets began to notice each other and oriented themselves in a more orderly fashion. The researchers continued to drop the temperature, until they reached a point where the tiny magnets appeared almost frozen. A similar process can be observed in water molecules as water freezes into ice.
Laura Heyderman, head of the research team at PSI, was surprised by these observations. "We were surprised and excited. Only complex systems are able to display phase transitions," explained Heyderman in a statement. "We were fascinated by the fact that our synthetic material displayed this everyday phenomenon.”
The measurements the researchers used to observe the nanomagnets’ magnetic orientation can only be conducted at the PSI. Located in Switzerland, PSI is designed to complement the high-energy experiments conducted at CERN’s Large Hadron Collider (LHC). The facility’s world-class equipment includes an instrument – known as the Swiss Muon Source (SμS) – which uses muon beams acting as magnetic probes to reveal magnetic properties on a nanoscale.
To take this initial experiment to the next level, the researchers may try to influence the phase transitions by experimenting with the size, shape, and arrangement of the nanomagnets. This could allow for the creation of new states of matter, and even new applications for the material. Individual atoms in natural materials cannot be rearranged on such a grand scale, but the advantage of this new synthetic material is that it can be customized. "The beauty of it all: tailored phase transitions could enable metamaterials to be adapted specifically for different needs in future," explains Heyderman.
Complex systems can enable new types of information transfer, but with its adaptability, this new metamaterial could be the wave of the future. Apart from facilitating information transfer, this material has many other potential uses. It could be useful in data storage, spintronics, or even in sensors that measure magnetic fields. We could even see it used in future computer technology.
The research was published in the journal Nature Communications.