Casey Miller
(October 30, 2015) A
promising new metal alloy system could lead to commercially viable magnetic
refrigerants and environmentally friendly cooling technologies, according to a
scientist at Rochester Institute of Technology.
Casey Miller, head of RIT’s materials science and
engineering program, and his colleagues published their findings in the Oct. 28
issue of Scientific Reports, an online open-access journal from the publishers
of Nature. Miller’s work in this area also led to an international
collaboration that published in Applied Physics Letters on Oct. 6, and which
was selected as an Editor’s Pick, making it free to any reader.
The study published in Scientific Reports explores an
iron-based alloy as a component of next-generation cooling technologies. The
materials use magnetic fields to change a refrigerant’s temperature without the
coolant gases associated with global warming. The thermodynamic phenomenon,
called “magnetocaloric effect,” makes magnetic refrigeration an environmentally
friendly and efficient alternative to current cooling technologies.
The alloy is a substitute for metals made from rare-earth
elements, predominantly produced in China and increasingly used in modern
magnets. The supply and cost of rare-earth metals are susceptible to
geopolitical tensions that hamper the commercial viability of new magnetic
refrigeration technologies, the authors reported. Transition metals typically
offer supply chain stability and are cheaper by weight than rare-earths, they
said.
“Our work is a great example of President Obama’s Materials
Genome Initiative in action,” Miller said. “We created alloys containing four
and five different elements whose properties helped our theory collaborators
develop a calculation that predicts the magnetic properties of a larger set of
compounds that have not yet been synthesized. Now we have identified hundreds
of new alloy combinations that could be useful.”