Oxidation state mapping


HAADF image of a phase transformations between magnetite (Fe3O4), ilmenite (FeTiO3) and rutile (TiO4). In the EELS map, the red color corresponds to Fe2,5+ in the magnetite, green color corresponds to the Fe2+ and Ti4+ in octahedral coordination in ilmenite and blue color corresponds to Ti4+ in rutile. The reference ELNES spectra used to fit the spectrum image are given in the same color code. They have been obtained with energy resolution of 140 meV with monochromator excited.


Maya Marinova (PMEL), Hugues Leroux (MTP-UMET)

EELS mapping at atomic resolution

High resolution HAADF image of an oxide heterostructure LaAlO3/Eu2Ti2O7 and EELS intensity maps of the La-M5,4 edge at 832 eV (red), the Ti-L3,2 edge at 456 eV (green) and Eu-M5,4 edge at 1131 eV (blue) at the interface between the two layers. The atomically resolved EELS maps clearly indicates the presence of the cationic and structural defects in the Eu2Ti2O7 layer close to the interface with the LaAlO3 substrate. The EELS maps have been taken with 0.9 eV resolution at the zero loss peak and a dispersion of 1 eV/ch. In a more general manner atomically resolved elemental mapping in the EELS mode can be used to investigate the chemical and structural nature of interfaces in oxides, as well as interdiffusion and the nature of different cationic and structural defects.

 Marielle Huvé (MISSP-UCCS), Sebastien Saitzek (CMNM – UCCS), Maya Marinova (PMEL)