Probing Oxygen Motion in Disordered Anionic Conductors with 17O and 51V MAS NMR Spectroscopy
Namjun Kim,
Clare P. Grey*
Identification of the local environments of the ions in
a solid-state electrolyte that contribute to the ionic conductivity or
remain trapped in the lattice represents a challenge for many experimental probes of structure. We show that high-resolution 17O magic angle spinning nuclear magnetic resonance (MAS
NMR) spectra may be obtained even from the highly disordered, layered
materials
-Bi4V2O11 and
-Bi4V1.7Ti0.3O10.85,
in which the different oxide sites in the lattice may be distinguished.
The sites responsible for anionic conduction were determined directly
from the variable-temperature 17O NMR spectra, and
correlation times for motion were estimated. Double-resonance
17O/51V NMR methods were used as confirmation
of the assignments of the resonances and as a second experimental probe
of motion that is sensitive to mobility involving oxide ion hops
between the same crystallographic sites.
Department of Chemistry, State University of New York at Stony
Brook, Stony Brook, NY 11794-3400, USA.
*
To whom correspondence should be addressed. E-mail:
cgrey{at}sbchem.sunysb.edu