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Colóquios 2014

Evento 

Título:
Towards Revealing the Magnetoelectric Effect in CuO
Quando:
24.06.2014 16.00 h
Onde:
Anfiteatro Antônio Cabral - Porto Alegre
Categoria:
Colóquios 2014

Descrição

Vassil Skumryev

Departament de Física, Universitat Autónoma de Barcelona (UAB), and
Institut Cátala de Recerca i Estudis Avançats (ICREA), Catalunya (Spain)


Apart from being so far the only known binary compound that is
multiferroic (i.e., coexisting long range magnetic and polar orders),
CuO has a much higher transition temperature into the multiferroic
state, 230 K, than any other known material in which the electric
polarization is induced by magnetic order (typically in the range of
30-40 K). Though the magnetically induced ferroelectricity of CuO is
firmly established, no magnetoelectric effect has been observed so
far, at least as a crosstalk between bulk magnetization and
polarization counterparts.

In this talk, based on unpublished results (from bulk magnetic and
electric polarization characterization, neutron diffraction and
ultrasound velocity in magnetic fields as high as 90 T) I will
demonstrate that high enough magnetic fields could alter the spiral
plane of the magnetic moments in the multiferroic phase of CuO and
affect the electric polarization. Furthermore, close to the first
order magnetic transition from commensurate (paraelectric) to
incommensurate (ferroelectric) magnetic structures, at 213 K, even
relatively weak magnetic field could affect the magnetic order and
cause remarkable polarization changes.


Vassil Skumryev is a Research Professor at Institut Cátala de Recerca
i Estudis Avançats (www.icrea.cat), and at the Universitat Autònoma de
Barcelona. He received a PhD from the University of Sofia (Bulgaria)
in 1983. Prior to joining ICREA in 2003, he had long term appointments
at Trinity College (Dublin, Ireland), University of Delaware (USA),
Max-Plank Institute für Metalforschung (Stuttgart, Germany), and The
Royal Institute of Technology (Stockholm, Sweden). He has worked in a
broad range of magnetic materials and phenomena publishing over 120
scientific papers (incl. Phys. Rev. Letters, Physics Reports, Phys.
Rev. B, Nature). His current research interest includes magnetically
frustrated systems as well as magnetoelectric materials and interface
phenomena in nanostructures of such materials.

Vassil Skumryev (vassil.skumryev@uab.es) is visiting the Laboratório
de Magnetismo, Instituto de Física, UFRGS, within the CNPq
"Pesquisador Visitante Especial" program.

Local

Venue:
Anfiteatro Antônio Cabral
Cidade:
Porto Alegre
Estado:
Rio Grande do Sul
País:
País: br

Descrição

Descrição não disponível
Sexta, Dezembro 03, 2021