Scientists in the US have uncovered that hematite features a rare and emerging form of magnetism, which reportedly paves the way for spintronic technologies technologies that could transform data processing and storage.<\/p>\n
The discovery, made by researchers at the Oak Ridge National Laboratory (ORNL), provided one of the clearest experimental evidence of altermagnetism, a newly identified third form of magnetism first proposed in 2022. <\/p>\n
Hematite, an abundant iron oxide better known as rust, and its one of the most common minerals on Earth. It is stable beyond 1,200 degrees Fahrenheit, which makes it a great fit for room-temperature spintronics without heavy cooling. <\/p>\n
\u201cHematite is abundant, chemically stable and nontoxic,\u201d Qiyang Sun, PhD, project lead and a postdoctoral researcher in ORNL, said. \u201cBy confirming its altermagnetic nature, we open a new platform for engineers to design high-speed, low-power quantum electronics using materials that are inexpensive and widely available.\u201d <\/p>\n
Inside hematite\u2019s quantum state<\/p>\n
Altermagnets, unlike conventional and antiferromagnets, are magnetic materials in which\u00a0electron\u00a0spins<\/a> align in opposite directions. This allows pure spin currents to flow without electric charge, making them ideal for spintronic applications<\/p>\n Meanwhile, spintronics, or magnetoelectronics<\/a>, is a technology that relies on the spin of electrons rather than their charge to process and store data, which could enable devices that operate faster while consuming far less energy than modern electronics.<\/p>\n<\/p>\n However, identifying practical and suitable materials for spintronic uses has so far remained a huge challenge. Now, to verify hematite\u2019s properties, the researchers turned to the Spallation Neutron Source (SNS), one of the world\u2019s most advanced neutron research facilities.<\/p>\n At the site, the team used a technique known as inelastic neutron scattering<\/a>, that is defined as an event where neutrons lose or gain energy by transferring energy to form a sample<\/a>. This way the scientists probed the material\u2019s internal magnetic dynamics at the atomic level. <\/p>\n While neutrons carry no electric charge, they possess a magnetic moment and are uniquely suited to studying magnetism. This is how the researchers analyzed spin waves (collective excitations that move through a material\u2019s magnetic structure).<\/p>\n Powering future technology<\/p>\n The results showed a distinct splitting in the energy of these spin waves, a subtle but definitive sign of altermagnetism. The phenomenon, called magnon splitting, cannot be captured using other experimental techniques. <\/p>\n \u201cInelastic neutron scattering<\/a> is the only method capable of resolving these fine spectral features,\u201d Sun said. \u201cIt provides simultaneous momentum and energy resolution, which allowed us to detect the subtle magnon splitting that defines altermagnetism.\u201d<\/p>\n The research combined experiments with modeling using ORNL\u2019s Sunny software<\/a>, as well as high-performance computing. The software was built to study quantum magnetism.<\/p>\n<\/p>\n \u201cThe confirmation of altermagnetism in hematite \u2013 a material as common as rust \u2013 demonstrates that a potential component for the next revolution in high-speed, low-power quantum electronics may already be all around us,\u201d Sun concluded in a press release<\/a>.<\/p>\n According to the researchers, the findings could reshape electronic design. They believe that charge-free spin currents could reduce energy loss and heat, as well as boost efficiency. Future work will explore how spin-wave gaps influence heat transport in hematite. <\/p>\n