The trail to a new multiferroic started with the theories of a U.S.
Department of Energy's (DOE) Argonne National Laboratory scientist and ended
with a multidisciplinary collaboration that created a material with potential
impact on next generation electronics.
Argonne scientist Craig Fennie's principles of microscopic materials design
predicted that the high pressure form of FeTiO3 would have both weak ferromagnetism
and ferroelectric polarization, an unusual combination in a single material.
"We were able to take the theory and, through targeted synthesis and measurement,
prove that FeTiO3 has both weak ferromagnetism and ferroelectricity, just as
Craig predicted," Argonne scientist John Mitchell said. "Success in
this materials design and discovery project would not have been possible without
a collaborative team involving several disciplines and talents from across the
lab and indeed the country."
Scientists from Argonne's materials science division and Center for Nanoscale
Materials along with scientists from Pennsylvania State University, University
of Chicago and Cornell University used piezoresponse force microscopy, optical
second harmonic generation and magnetometry to show ferroelectricity at and
below room temperature and weak ferromagnetism below 120 Kelvin for polycrystalline
FeTiO3 synthesized at high pressure.
Multiferroic materials show both magnetism and polar order, which are seemingly
contradictory properties. Magnetic ferroelectrics may have applications in memory,
sensors, actuators and other multifunctional devices by acting as magnetic switches
when their electric fields are reversed.
Multiferroic - add one
This project was recently published in Physical Review Letters and will be
featured in the upcoming Advanced Photon Source annual report.
Funding for this research was provided by the U.S. Department of Energy, Office