Seminário em Física da Matéria Condensada do Departamento de Física dos Materiais e Mecânica
Electric-field control of magnetism: The case of multiferroic BiFeO3
Dr. Rogerio de Sousa
Department of Physics and Astronomy, University of
Victoria, Victoria, B.C., V8W 2Y2, Canada
Data: 16 de julho de 2014 (hoje)
Horário: às 16h
Local: Sala de Seminários José Roberto Leite
The ability to control magnetism using electric fields is of great
fundamental and practical interest. It may allow the development of
ideal magnetic memories with electric write and magnetic read
capabilities, as well as logic devices based on spin waves that
dissipate much less energy. Multiferroic materials with coexisting
magnetic and ferroelectric phases have emerged as the natural physical
system to search for this kind of control. However, all demonstrations
so far are based on changing the ferroelectric state in order to
affect magnetism. I will show that in bismuth ferrite (BiFeO3 or BFO)
the combination of multiferroicity with strong spin-orbit interaction
at the bismuth ion sites leads to a qualitatively different kind of
control, based on the appearence of a magnetic anisotropy that is
linear in the external E-field. This allows E-field control of
magnetism without changing the ferroelectric state, and may lead to
new spin-based devices with reduced energy dissipation.
Profs. Fernando Garcia (DFAP), Luís Gregório Dias da Silva (DFMT) e Rafael de Freitas (DFMT)
