Titanium and gold aren’t magnetic—unless you combine them just so.
Scientists at Rice University did so and discovered what is a first of its kind: an itinerant antiferromagnetic metal—TiAu—made from nonmagnetic constituent elements.
While the uses for this particular magnet have yet to be determined, the discovery could enhance the scientific understanding of magnetism.
An open-access paper about the research appears in Nature Communications.
Very Cold Temperatures
This is not the kind of magnet one would stick to a refrigerator. Magnetic order only appears in TiAu when the metal is cooled to 36 kelvins, about minus 395 degrees Fahrenheit.
“Magnetization is a function of temperature,” says lead author Eteri Svanidze. “The magnet’s ordering temperature appears as an anomaly in the smooth curve we see in such magnetization measurements.”
For common magnets, that temperature is generally hundreds of degrees Fahrenheit, way hotter than any kitchen. But the energy and temperature scale in unconventional magnets, like the few that have no magnetic elements, are drastically reduced.
Svanidze says the magnets will enhance studies of other important physics, like phase transitions (as in solid-to-liquid or liquid-to-gas) that take place at absolute zero, called quantum phase transitions.
50 Years Later
TiAu is only the third known itinerant magnetic metal made with no magnetic elements. The other two, both ferromagnets that activate their magnetic order at temperatures even colder than TiAu, were discovered half a century ago. Part of the reason for the long gap is that TiAu is challenging to make.
