Reference : Dynamic and structural properties of orthorhombic rare-earth manganites under high pr...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Physics
http://hdl.handle.net/10993/21322
Dynamic and structural properties of orthorhombic rare-earth manganites under high pressure
English
Mota, D. A. [Universidade do Porto, Portugal > Instituto de Fisica dos Materiais da Universidade do Porto and Institute of Nanoscience and Nanotechnology, Departamento de Fisica e Astronomia da Faculdade de Ciencias]
Almeida, A. [Universidade do Porto, Portugal > Instituto de Fisica dos Materiais da Universidade do Porto and Institute of Nanoscience and Nanotechnology, Departamento de Fisica e Astronomia da Faculdade de Ciencias]
Rodrigues, V. H. [Universidade de Coimbra, Portugal > Centro de Estudos de Materiais por Difracao de Raios X, Departamento de Fısica, Faculdade de Ciencias e Tecnologia]
Costa, M. M. R. [Universidade de Coimbra, Portugal > Centro de Estudos de Materiais por Difracao de Raios X, Departamento de Fısica, Faculdade de Ciencias e Tecnologia]
Tavares, P. [Universidade de Tras-os-Montes e Alto Douro, Vila Real, Portugal > Centro de Quımica—Vila Real, Departamento de Quımica]
Bouvier, P. [Centre National de la Recherche Scientifique, Université Grenoble-Alpes, France > Laboratoire des Matériaux et du Génie Physique]
Guennou, M. [Centre de Recherche Publique Gabriel Lippmann, Belvaux, Luxembourg > Département Science et Analyse des Matériaux]
Kreisel, Jens mailto [University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit > ; Centre de Recherche Publique Gabriel Lippmann, Belvaux, Luxembourg > Département Science et Analyse des Matériaux]
Agostinho Moreira, J. [Universidade do Porto, Portugal > Instituto de Fisica dos Materiais da Universidade do Porto and Institute of Nanoscience and Nanotechnology, Departamento de Fisica e Astronomia da Faculdade de Ciencias]
2014
Physical Review B
90
5
Yes (verified by ORBilu)
International
1098-0121
[en] We report a high-pressure study of orthorhombic rare-earth manganites AMnO3 using Raman scattering (for
A = Pr, Nd, Sm, Eu, Tb, and Dy) and synchrotron x-ray diffraction (XRD), for A = Pr, Sm, Eu, and Dy.
In all cases, a phase transition was evidenced by the disappearance of the Raman signal at a critical pressure
that depends on the A cation. For the compounds with A = Pr, Sm, and Dy, XRD confirms the presence of
a corresponding structural transition to a noncubic phase, so that the disappearance of the Raman spectrum
can be interpreted as an insulator-to-metal transition. We analyze the compression mechanisms at work in the
different manganites via the pressure dependence of the lattice parameters, the shear strain in the ac plane, and
the Raman bands associated with out-of-phase MnO6 rotations and in-plane O2 symmetric stretching modes.
Our data show a crossover across the rare-earth series between two different kinds of behavior. For the smaller
A cations considered in this study (Dy and Tb), the compression is nearly isotropic in the ac plane, with only
small evolutions of the tilt angles and cooperative Jahn-Teller distortion. As the radius of the A cation increases,
the pressure-induced reduction of Jahn-Teller distortion becomes more pronounced and increasingly significant
as a compression mechanism, while the pressure-induced tilting of octahedra chains becomes conversely less
pronounced. We finally discuss our results in light of the notion of chemical pressure and show that the analogy
with hydrostatic pressure works quite well for manganites with the smaller A cations considered in this paper but
can be misleading with large A cations.
http://hdl.handle.net/10993/21322
10.1103/PhysRevB.90.054104
Times Cited: 1 1
Journal Article

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