Scientists transform heat into motion by magnetic system


A group of international scientists discovered a magnetic system to transform heat into motion. These techniques help in nanoscale devices for data storages and sensors in future.

The study organized by team, among them Professor Gino Hrkac from the University of Exeter, developed magnetic system known as ratchet. It separates thermal energy with a specific gear. The magnetic system built with artificial spin ice material. It contains tiny magnets 200 times smaller than human hair. Magnets created with nickel-iron alloy Permalloy.

The scientists made magnetic energy into rotation of magnetization. During the process rotations occurred only in two directions.

The research author Sebastian Gliga from University of Glasgow, recalls “The system we have studied is an artificial spin ice. A class of geometrically frustrated magnetic materials. Surprised to see that the geometry of the interactions can be tailored. To achieve an active material that acts as a ratchet.”

Professor Gino Hrkac says “We tried to understand for quite some time how the system worked before realized that the edges created an asymmetric energy potential.” This asymmetry is reflected in the distribution of the magnetic field. At the boundaries of the nanomagnet array and causes the magnetization to rotate in a preferred direction.

Magnetic Dichroic Effect

They implemented x-rays known as magnetic dichroic effect to capture the process of magnetic state of the system. However, the measurements carried out at the synchrotron light source SLS at the Paul Scherrer Institute in Switzerland and at the Advanced Light Source, Lawrence Berkeley National Laboratory in the United States.

The angular momentum maintained and also spin considered as form of angular momentum. Further, the change in the magnetic moment of the system in principle can induce a physical rotation of the system through the Einstein-de Haas effect.

It helps finding applications in magnetic memory where bits stored through local heating with laser pulses.

According to Professor Laura Heyderman of the ETH Zurich and Paul Scherrer Institute: “Artificial spin ice has mainly used to answer scientific questions. Concerning the physics of frustration. This is a nice demonstration of how artificial spin ice can be a functional material and provides a step towards applications.”

Moreover, the phenomenon observed in two-dimensional magnetic structures. It might be practical use in nanoscale devices, such as magnetic nanomotors, actuators, or sensors.