LiIn₂SbO₆: A New Rutile-Related Structure Type with Unique Ion Channels

Abstract

Single crystals of LiIn 2 SbO 6 (LIAO) have been synthesized using a Li 2 MoO 4 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 LiSbO 3 . The relationship between this new structure and LiSbO 3 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.

Li/Na substitution and Yb3+ co-doping enabling tunable near-infrared emission in LiIn2SbO6:Cr3+ phosphors for light-emitting diodes

“…Figure 1 C shows the Rietveld refinement result of LiIn 1.97 SbO 6 :0.03Cr 3+ with satisfactory residual factors R wp = 6.66%, R p = 5.08%, R B = 1.05%, and χ 2 = 3.73%. The detailed parameters are listed in Tables S1 and S2 , which emphasizes the purity of target phase and the rutile-related lattice structure with a space group of Pnnm ( Flynn et al., 2020 ). The inset in Figure 1 C shows the substitute model of Cr 3+ in LiIn 2 SbO 6 host that formed by edge-sharing InO 6 and SbO 6 octahedrons while Li + ions are located at channels and play a role in balancing charge.…”

Solid-State NMR of Spin-9/2 Nuclei 115In and 209Bi in Functional Inorganic Complex Oxides

“…One possible explanation for the deviation between the calculated and experimental results relates to disorder on the lithium site. Lithium coordination in LiIn 2 SbO 6 was previously probed by6 Li and7 Li NMR where it was determined that the unique tunnel pattern of this rutile-like structure hosts lithium ions in split tetrahedral sites 19. This finding ran counter to a previous proposal that LiIn 2 SbO 6 is simply a cation-ordered variant of LiSbO 3 with octahedral LiO 6 sites.…”

“…[12][13][14][15][16] Lithium indium oxides have been studied as prospective solid electrolytes for all-solid-state lithium-ion batteries. [17][18][19] Substituted versions of fluorite bismuth oxide (-Bi 2 O 3 ) [20][21][22][23] and Aurivillius-type mixed-metal bismuth oxides 20,24,25 host some of the highest known high oxygen-ion conductivities. Bismuthate glasses are non-toxic candidates to replace lead oxide in zero-stress optic materials.…”

“…LiIn 2 SbO 6 is a rutile-like structure with a channel arrangement that is unique amongst rutile phases (Figure 1a). 19 Solid-state NMR. NMR spectra were recorded in a 9.4 T static magnetic field with a Bruker Avance III spectrometer and a 4.0 mm Bruker HX probe with the exception of 23 Na and fast MAS 69,71 Ga measured with a 1.6 mm Phoenix HFX probe.…”

“…80 LiIn 2 SbO 6 , BiAlTeO 6 , and BiGaTeO 6 crystal structures were used as starting models. 19,31 Prior to the NMR calculations, atomic positions and lattice were optimized until the force on any atom was smaller than 1 meV Å −1 . All calculations used a planewave energy cutoff energy of 700 eV and a Monkhorst−Pack 81 grid with a spacing finer than 2π × 0.03 Å −1 to sample the Brillouin zone.…”