Vanadium valency and hybridization in V-doped hafnia investigated by electron energy loss spectroscopy

Abstract

PACS. 61.50.Nw Crystal stoichiometry – 71.28.+d Narrow-band systems; intermediate-valence solids – 78.70.Dm X-ray absorption spectra,

Growth and structure of PbVO3 thin films

“…12,13 Since PVO has a strong tetragonal distortion, it induces one of the two apical oxygen atoms to separate from the normal VO 6 octahedron and causes the formation of corner-shared square pyramids. It is well known that the valence state of the V ion is not the only factor determining the EEL spectra of V-L edges and that the crystal structure can also play an important role in determining the spectra.…”

Probing non-dipole allowed excitations in highly correlated materials with nanoscale resolution

“…2. Energetic diagram for d 8 NiO structure : Left part shows the LS terms for a d 8 configuration of an isolated atom. The right part shows the symmetry term when an O h crystal field is introduced.…”

“…In this scope, the electron energy loss spectroscopy (EELS) combined with the capability of (scanning) transmission electron microscopes ((S)TEM) have already been used in order to characterise the electronic structure of such materials on a nanometer scale [2,3,7]. Recently, the local determination of the transition metal valence by mean of the study of EELS TM 2p excitations has become a wide-spread technique [8,9].…”

“…In this scope, the electron energy loss spectroscopy (EELS) combined with the capability of (scanning) transmission electron microscopes ((S)TEM) have already been used in order to characterise the electronic structure of such materials on a nanometer scale [2,3,7]. Recently, the local determination of the transition metal valence by mean of the study of EELS TM 2p excitations has become a wide-spread technique [8,9].Among the various spectral domains, which have been probed for studying strongly correlated material, the low-energy domain (o5 eV) is of increasing interest. In particular, d-d excitations, which correspond to excitations within the open d shell have been investigated and can provide informations on the ground-state properties.…”

Electron energy-loss spectroscopy in the low-loss region as a characterization tool of electrode materials

“…On the other hand, the high-loss region-i.e., the core-loss region above 100 eV-describes excitations of electrons from core levels to unoccupied band-like electronic states. This excitation process allows to get back to various local properties relative to the excited atom oxidation states [7,8], local symmetry through d-level splitting in transition metals [9], anisotropy in materials [10].…”