cm0c01491_si_003.cif (77.82 kB)
LiIn2SbO6: A New Rutile-Related Structure Type with Unique Ion Channels
dataset
posted on 2020-05-22, 16:35 authored by Steven Flynn, Sheel Sanghvi, Matthew L. Nisbet, Kent J. Griffith, Weiguo Zhang, P. Shiv Halasyamani, Sossina M. Haile, Kenneth R. PoeppelmeierSingle crystals of LiIn2SbO6 (LIAO) have
been synthesized using a Li2MoO4 flux and characterized
with X-ray diffraction. The compound crystallizes in a new structure
type with a rutile-related framework. Like others in the rutile-related
family, LIAO is formed of chains of edge-sharing octahedra. The chain
structure, with a width that alternates between single and double
octahedra, has not previously been reported in a rutile-related material.
The framework is formed via corner sharing by the chains in a checkerboard
arrangement, with Li+ residing in tetrahedral sites in
the resulting, identically-alternating channels. Solid-state 6/7Li NMR spectroscopy and ab initio spectral calculations
verify the presence of tetrahedrally coordinated lithium. The solution
determined here contradicts previous reports of this material as a
cation-ordered variant of LiSbO3. The relationship between
this new structure and LiSbO3 and others in the rutile-related
family is discussed. Variable temperature powder X-ray diffraction
and diffuse reflectance show that LIAO has high thermal stability
and a large direct band gap of 3.9 eV. AC impedance spectroscopy reveals
that LIAO is a relatively poor Li conductor, displaying a conductivity
of 1.3 × 10–7 S/cm at 623 K, along with an
activation energy for charge transport of 1.1 eV. This material presents
an opportunity to explore a new subfamily of rutile-related materials
in which alternating-width chains may provide an independent avenue
for tuning desired properties.