Researchers from Temple University and the University of Maryland in the United States have discovered a new type of magnet that expands in volume when placed in a magnetic field, and wastes negligible amounts of heat during energy harvesting. This new discovery has enormous potential for application, not only to replace existing technologies, but also to create new applications.

 

Hashe Dipp Chopra, the head of the Department of Mechanical Engineering and the Laboratory of Materials Genomics and Quantum Devices at Temple University, and Manfred Utig, a professor in the Department of Materials Science and Engineering at the University of Maryland, published their research results in the journal Nature on the 21st. Chopra said, "Our discovery fundamentally changed our understanding of a specific type of magnet that has been known since 1841

 

In the 1840s, British physicist James Joule discovered that iron-based magnetic materials would change their shape but maintain their volume when placed in a magnetic field. This phenomenon is called "Joule magnetostriction", and in the 175 years since its discovery, all magnets have exhibited this characteristic.

 

We have discovered a new type of magnet, which we call non Joule magnetostrictive magnets. In a magnetic field, their volume undergoes significant changes, "said Chopra." Moreover, these non Joule magnetostrictive magnets also have extraordinary abilities to collect or convert energy through heat loss

 

Chopra and Utig heated a specific iron-based alloy in a furnace to approximately 760 degrees Celsius for 30 minutes, then rapidly cooled it to room temperature, at which point the material exhibited non Joule magnetostriction behavior.

 

They found that the heat-treated material contains tiny honeycomb structures that have never been seen before, which is the key to its non Joule magnetostriction reaction in a magnetic field. Wutig added, "Knowing this unique structure will enable researchers to develop new materials with the same properties

 

Researchers point out that due to the limitations of Joule magnetostriction, conventional magnets can only be used as actuators to apply force in one direction. Even if only actuated in two directions, a large number of bulky magnets are required, which increases volume and reduces efficiency. Non Joule magnetostrictive magnets can expand in all directions simultaneously, making it easy to manufacture compact omnidirectional actuators.

 

Due to their energy-saving properties, these new magnets can be used to create a new generation of sensors and actuators with extremely low heat loss, which are applied in fields such as aerospace, automotive, biomedicine, national defense, space exploration, and robotics.