Newfound 'altermagnets' shatter the magnetic status quo

[Judi Lynn]

The materials have attracted attention for their versatile potential

By Emily Conover

APRIL 25, 2024 AT 6:00 AM

For the first time in nearly a century, physicists have identified a brand new type of magnetic material.

Crack open a physics textbook and you may read that scientists classify magnetic materials into two main types: ferromagnets and antiferromagnets. Ferromagnets are what most people think of when magnets come to mind. These materials possess a magnetic field that lets them hold up photos on a refrigerator or cause a magnetic compass to point north. Antiferromagnets have no external magnetic field but have other magnetic quirks.

Now, that classic pair has become a trio. Physicists have reported a new class of magnetic materials called altermagnets, which could lead to new technologies such as faster, more efficient computer hard drives.

Even though the idea behind altermagnets is extremely simple, says theoretical physicist Igor Mazin of George Mason University in Fairfax, Va., “somehow … nobody thought about this possibility” until recently. The fact that a third magnetic category could have remained unnoticed this long, “it’s very surprising to me.”

That’s because the study of magnetic materials is an ancient science. Ferromagnets have been known for thousands of years. Lodestone, a magnetized form of the mineral magnetite, fascinated the ancient Greeks. The Chinese forged the magnetized mineral into the first compasses in the fourth century B.C. (SN: 1/28/11). Antiferromagnets were discovered in the 1930s.

More:
https://www.sciencenews.org/article/altermagnets-new-magnetic-class

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1. Interesting bit from the article ...

What’s more, whereas ferromagnets tend to be metals, altermagnets can be made of a variety of material types (SN: 1/11/23). Manganese telluride, for example, is a semiconductor. Because semiconductors are used to make computer chips, scientists hoped that a magnetic material that is also a semiconductor might allow for the possibility of combining a memory and processor in one material (SN: 10/4/13).