Rice University scientists combine titanium and gold to make
itinerant antiferromagnet
(July 14, 2015) Titanium and gold are usually not magnetic and
cannot be magnets – 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.
The research by the lab of Rice physicist Emilia Morosan has
already been cited as a textbook example of how magnetism arises in metals.
While the uses for this particular magnet have yet to be determined, the Rice
discovery could enhance the scientific understanding of magnetism.
An open-access paper about the research appears this week in
Nature Communications.
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,” said 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.