Rice’s Morosan wins NSF CAREER award
Physicist sets sights on discovery of novel magnetic materials

BY JADE BOYD
Rice News staff

Emilia Morosan’s career is starting to heat up. The Rice physicist, who uses furnaces in her lab to create compounds with novel magnetic properties, has landed a highly coveted CAREER Development Award from the National Science Foundation (NSF).

CAREER awards support the research and educational development of young scholars who are likely to become leaders in their field. Each comes with a five-year grant of up to $550,000. These are among the most competitive grants awarded by the NSF, which gives out only about 400 per year across all disciplines.

For her CAREER grant, which was awarded under the American Recovery and Reinvestment Act, Morosan has an ambitious goal: discover and perfect the synthesis for compounds that are “itinerant ferromagnets” without magnetic elements in their composition. Only two such unusual compounds are known to exist. Unconventional superconductivity and even other exotic phase transitions are believed to occur in these compounds, and Morosan is confident that physicists can learn much from the materials if they have more of them to study.

	JEFF FITLOW
	Rice physicist Emilia Morosan pulls a red-hot crucible from a furnace in her lab. The condensed-matter physicist uses the furnaces to create metallic compounds with novel magnetic properties.

“Magnetism has been studied since antiquity, but many fundamental unanswered questions remain, particularly with regard to unconventional materials like itinerant ferromagnets,” Morosan said.

When itinerant ferromagnets are cooled below a critical temperature, they go through a phase transition. By appropriately manipulating these compounds, the phase transition can be tuned to absolute zero temperature. These are fundamentally different from the more familiar phase transitions, for example, liquid to solid as water freezes. In the case of the zero-temperature phase transitions, quantum and not thermal fluctuations are now at play, and they are therefore called quantum phase transitions.

In ferromagnetic materials — like common refrigerator magnets — the magnetic “moments” of each atom are perfectly aligned. The reason that other materials, like plastic or silver spoons, don’t stick to the refrigerator is that they have no magnetic ”moments.”

In itinerant ferromagnets with no magnetic constituents, magnetism occurs even though there are no magnetic ”moments” to be aligned. The only two such systems known are scandium-indium and zirconium-zinc.

In 2008, Rice faculty earned seven CAREER awards from the National Science Foundation. That was enough to tie Rice for second place among private American universities in total number of CAREER grants awarded in fiscal ’08; the percentage of Rice faculty members who earned CAREER Awards far outstripped any other U.S. institution.

“This is the result of a collective behavior that cannot be traced back to any single atom’s moment,” Morosan said. “The theories that attempt to explain this behavior are incomplete at best. It would clearly help to have new materials to study.”

In her lab, Morosan uses both traditional furnaces and arc furnaces to create metallic compounds. Based on the partial theories available, she plans to systematically create and test crystalline compounds containing two or more transition metals in search of new itinerant ferromagnets that could help physicists better understand the underlying physics of quantum phase transitions.

It may sound like hunting for a needle in a haystack, but Morosan is confident that undiscovered itinerant ferromagnets are out there, and she believes she has a good chance of finding some of them during the course of her CAREER grant program.

“The worst thing that can happen is that I end up discovering new compounds that I wasn’t looking for to begin with,” she said. “I will take that failure mode anytime.”