Ab-initio multiplet calculation of oxygen vacancy effect on Ti-L-2,L-3 electron energy loss near edge structures of BaTiO3

The effect of oxygen vacancy on Ti-L_[2, 3] electron energy-loss near-edge structures (ELNES) of BaTiO_3 was theoretically investigated through ab initio multiplet calculation. The presence of an oxygen vacancy influences spectral features not only at the nearest neighbor Ti site but also at Ti sites further from the oxygen vacancy. The effects of different oxygen vacancy concentrations were also investigated. Based on this study, it was concluded that the detection limit for oxygen vacancy with Ti-L_[2, 3] ELNES is approximately 1%

Epitaxial Growth of LiMn₂O₄ Thin Films by Chemical Solution Deposition for Multilayer Lithium-Ion Batteries

Cathodic LiMn₂O₄ films on various single-crystal substrates for use in thin-film Li-ion batteries prepared using a chemical solution deposition method are reported. Transmission electron microscopy is utilized to characterize the microstructures of the films. The results show that the film/substrate lattice misfit can affect significantly the quality of epitaxially grown grains of LiMn₂O₄. Using state-of-the-art high-angle annular dark-field imaging, the degree of coherency and lattice distortion at interfaces between LiMn₂O₄ and Au-coated and uncoated Al₂O₃ (0001) single-crystal substrates are examined at the atomic scale. When the lattice misfit is sufficiently small, fully coherent LiMn₂O₄/Au heterointerfaces form, although lattice strain to a distance of up to around 10 nm from the interface changes the symmetry of spinel LiMn₂O₄ from cubic to tetragonal. Such an interface in the LiMn₂O₄/Au/Al₂O₃ system facilitates high-quality epitaxial film growth to thicknesses of a couple hundred nanometers