Local structure of core−shell MnFe2O4+δ-based nanocrystals: cation distribution and valence states of manganese ions
Carregando...
Data
2017
Data de publicação:
Autores IPEN
Orientador
Título da Revista
ISSN da Revista
Título do Volume
É parte de
É parte de
É parte de
The Journal of Physical Chemistry C
Exportar
Resumo
We investigate the local structure of nanoparticles
based on a manganese ferrite core surrounded or not by a
maghemite layer obtained after hydrothermal surface treatment.
Results of X-ray powder diffraction (XRD) and neutron powder
diffraction (NPD) measurements are crossed with those of infield
Mössbauer spectroscopy and X-ray absorption spectroscopy
(XANES/EXAFS) to study the valence state of Mn ions and the
cation distribution at interstitial sites of the core−shell nanoparticle
structure. Linear combination fitting of XANES data
clearly indicates the existence of mixed valence states of Mn
cations in the Mn ferrite phase. As a direct consequence, it induces nonequilibrium cation distributions in the nanoparticle core
with the presence of a large amount of Mn cations at octahedral sites. The quantitative results of the inversion degree given by
NPD, Mössbauer spectroscopy measurements, and EXAFS are in good accordance. It is also shown that both the proportions of
each oxidation degree of Mn ions and their location at tetrahedral or octahedral sites of the spinel nanocrystal core can be
modified by increasing the duration of the surface treatment.
Como referenciar
MARTINS, FERNANDO H.; SILVA, FRANCISCARLOS G.; PAULA, FABIO L.O.; GOMES, JULIANO de A.; AQUINO, RENATA; MESTNIK-FILHO, JOSE; BONVILLE, PIERRE; PORCHER, FLORENCE; PERZYNSKI, REGIME; DEPEYROT, JEROME. Local structure of core−shell MnFe2O4+δ-based nanocrystals: cation distribution and valence states of manganese ions. The Journal of Physical Chemistry C, v. 121, n. 16, p. 8982-8991, 2017. DOI: 10.1021/acs.jpcc.6b09274. Disponível em: http://repositorio.ipen.br/handle/123456789/27753. Acesso em: 23 Apr 2024.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.