Crystal growth of a series of lithium garnets Ln{sub 3}Li{sub 5}Ta{sub 2}O{sub 12} (Ln=La, Pr, Nd): Structural properties, Alexandrite effect and unusual ionic conductivity

Journal Article · Sun Feb 15 04:00:00 EST 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2008.10.032· OSTI ID:21212192

Roof, Irina P; Smith, Mark D ^[1]; Cussen, Edmund J ^[2]

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1. Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States)
2. WestCHEM, Department of Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL (United Kingdom)

We report the single crystal structures of a series of lanthanide containing tantalates, Ln{sub 3}Li{sub 5}Ta{sub 2}O{sub 12} (Ln=La, Pr, Nd) that were obtained out of a reactive lithium hydroxide flux. The structures of Ln{sub 3}Li{sub 5}Ta{sub 2}O{sub 12} were determined by single crystal X-ray diffraction, where the Li{sup +} positions and Li{sup +} site occupancies were fixed based on previously reported neutron diffraction data for isostructural compounds. All three oxides crystallize in the cubic space group Ia3-bard (No. 230) with lattice parameters a=12.7735(1), 12.6527(1), and 12.5967(1) A for La{sub 3}Li{sub 5}Ta{sub 2}O{sub 12}, Pr{sub 3}Li{sub 5}Ta{sub 2}O{sub 12}, and Nd{sub 3}Li{sub 5}Ta{sub 2}O{sub 12}, respectively. A UV-Vis diffuse reflectance spectrum of Nd{sub 3}Li{sub 5}Ta{sub 2}O{sub 12} was collected to explain its unusual Alexandrite-like optical behavior. To evaluate the transport properties of Nd{sub 3}Li{sub 5}Ta{sub 2}O{sub 12}, the impedance data were collected in air in the temperature range 300{<=}T(deg. C){<=}500. - Graphical abstract: Crystal structure of garnets Ln{sub 3}Li{sub 5}Ta{sub 2}O{sub 12} (Ln=La, Pr, Nd). TaO{sub 6} polyhedra are shown in yellow and Ln{sup 3+} are shown as light blue spheres. Octahedrally and tetrahedrally coordinated Li{sup +} ions are shown in green and brown, respectively. Oxygen atoms are omitted for clarity.

• OSTI ID: 21212192
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 182; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CRYSTAL GROWTH
CRYSTAL STRUCTURE
IMPEDANCE
IONIC CONDUCTIVITY
LANTHANUM COMPOUNDS
LATTICE PARAMETERS
LITHIUM COMPOUNDS
LITHIUM HYDROXIDES
LITHIUM IONS
MONOCRYSTALS
NEODYMIUM COMPOUNDS
NEUTRON DIFFRACTION
OPTICAL PROPERTIES
PRASEODYMIUM COMPOUNDS
SPACE GROUPS
SPECTRA
TANTALATES
TEMPERATURE RANGE 0400-1000 K
X-RAY DIFFRACTION