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 00:00:00 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, Vol. 182, Issue 8; Other Information: DOI: 10.1016/j.jssc.2009.05.020; PII: S0022-4596(09)00228-X; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

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