Researchers at Rice University have identified a link between mechanical pressure and the magnetic properties of iron sulfide. By applying gentle compression to the crystal, the team observed simultaneous shifts in its magnetic signal and the way electricity moves through the material. This finding provides insight into a class of materials known as altermagnets.
Altermagnets act as a hybrid between standard magnets and antiferromagnets. While they do not produce a strong external magnetic field, they influence electron movement in ways beneficial for future electronic components. The iron sulfide samples tested by the team displayed the anomalous Hall effect, a phenomenon where current generates a sideways voltage without an external magnetic field.
Pengcheng Dai and his team used a specialized device to compress the crystal while monitoring internal magnetic changes. Using neutron beams at Oak Ridge National Laboratory, the researchers determined that pressure alters the most common magnetic orientations within the crystal. Although the primary magnetic order remains stable, the small, leftover magnetic moment decreases in response to the strain.
This experiment suggests that the anomalous Hall effect and the small magnetic moment are tied to the same physical mechanisms. The ability to tune these properties with simple mechanical strain holds potential for the field of spintronics. This area of physics works to store and process data using the magnetic characteristics of electrons, which could lead to devices with lower energy requirements and reduced magnetic interference.