Synthesis and structure analysis of tetragonal Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} with the garnet-related type structure

Journal Article · Sat Aug 15 04:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.05.020· OSTI ID:21370519

Awaka, Junji ^[1]; Kijima, Norihito; Hayakawa, Hiroshi; Akimoto, Junji ^[1]

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1. National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan)

We have successfully synthesized a high-purity polycrystalline sample of tetragonal Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12}. Single crystals have been also grown by a flux method. The single-crystal X-ray diffraction analysis verifies that tetragonal Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} has the garnet-related type structure with a space group of I4{sub 1}/acd (no. 142). The lattice constants are a=13.134(4) A and c=12.663(8) A. The garnet-type framework structure is composed of two types of dodecahedral LaO{sub 8} and octahedral ZrO{sub 6}. Li atoms occupy three crystallographic sites in the interstices of this framework structure, where Li(1), Li(2), and Li(3) atoms are located at the tetrahedral 8a site and the distorted octahedral 16f and 32g sites, respectively. The structure is also investigated by the Rietveld method with X-ray and neutron powder diffraction data. These diffraction patterns are identified as the tetragonal Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} structure determined from the single-crystal data. The present tetragonal Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} sample exhibits a bulk Li-ion conductivity of sigma{sub b}=1.63x10{sup -6} S cm{sup -1} and grain-boundary Li-ion conductivity of sigma{sub gb}=5.59x10{sup -7} S cm{sup -1} at 300 K. The activation energy is estimated to be E{sub a}=0.54 eV in the temperature range of 300-560 K. - Graphical abstract: Garnet-related Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} having tetragonal symmetry (I4{sub 1}/acd, no.142) has been successfully synthesized. Single crystals have been also grown by a flux method. The single-crystal X-ray diffraction analysis verifies that tetragonal Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} has the garnet-related type structure with the lattice constants of a=13.134(4) A and c=12.663(8) A and the fully ordered arrangement of Li atoms.

• OSTI ID: 21370519
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 8 Vol. 182; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
ALKALI METAL COMPOUNDS
CHALCOGENIDES
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTAL GROWTH
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALLOGRAPHY
CRYSTALS
DIFFRACTION
ENERGY
ENERGY RANGE
GARNETS
GRAIN BOUNDARIES
IONS
LANTHANUM COMPOUNDS
LATTICE PARAMETERS
LITHIUM COMPOUNDS
LITHIUM IONS
MICROSTRUCTURE
MILLI EV RANGE
MINERALS
MONOCRYSTALS
NEUTRON DIFFRACTION
OXIDES
OXYGEN COMPOUNDS
POLYCRYSTALS
RARE EARTH COMPOUNDS
SCATTERING
SILICATE MINERALS
SPACE GROUPS
SYMMETRY GROUPS
SYNTHESIS
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TETRAGONAL LATTICES
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
ZIRCONIUM COMPOUNDS