resumo
The evolution of the local Jahn-Teller distortion across the LaMnO3+Delta phase diagram was obtained using the perturbed angular correlation local probe technique. We found that upon doping, the local distortion decreases continuously with increasing doping and that no fully Jahn-Teller distorted Mn3+O6 octahedra are observed within the orthorhombic insulating phase. A local single-phase scenario is established for the orbital disordered orthorhombic crystallographic structure. We also show that the continuous weakening of the Jahn-Teller distortions is not limited to a single-phase environment and occurs in a similar manner within an undistorted rhombohedric matrix upon lowering the temperature.
palavras-chave
ORDER-DISORDER TRANSITION; OXYGEN-CONTENT; FUEL-CELLS; PEROVSKITE; CATALYSTS; LOCALIZATION; LA1-XSRXMNO3; TEMPERATURE; DIFFRACTION; DEFECTS
categoria
Physics
autores
Lopes, AML; Amaral, VS; Correia, JG; Araujo, JP
nossos autores
Vitor Brás Sequeira Amaral
Professor CatedráticoProjectos
MULTIFOX: Nanometric Probing and Modification of Multiferroic Oxides (PTDC/FIS/105416/2008)
Perturbed Angular Correlations and Electron Channeling Experiments at ISOLDE - applied materials research with nuclear techniques, training and development (CERN/FP/123585/2011)
agradecimentos
We thank Dr R Suryanarayanan from the LPCES-ICMMO, Universite Paris-Sud XI, Orsay, France, for the supply of the LaMnO