title: A synthesis and crystal chemical study of the fast ion conductor Li(7-3x)Ga(x)La3 Zr2O12 with x = 0.08 to 0.84.
abstract: Fast-conducting phase-pure cubic Ga-bearing Li7La3Zr2O12 was obtained using solid-state synthesis methods with 0.08 to 0.52 Ga(3+) pfu in the garnet. An upper limit of 0.72 Ga(3+) pfu in garnet was obtained, but the synthesis was accompanied by small amounts of La2Zr2O12 and LiGaO3. The synthetic products were characterized by X-ray powder diffraction, electron microprobe and SEM analyses, ICP-OES measurements, and (71)Ga MAS NMR spectroscopy. The unit-cell parameter, a0, of the various garnets does not vary significantly as a function of Ga(3+) content, with a value of about 12.984(4) Å. Full chemical analyses for the solid solutions were obtained giving: Li7.08Ga0.06La2.93Zr2.02O12, Li6.50Ga0.15La2.96Zr2.05O12, Li6.48Ga0.23La2.93Zr2.04O12, Li5.93Ga0.36La2.94Zr2.01O12, Li5.38Ga0.53La2.96Zr1.99O12, Li4.82Ga0.60La2.96Zr2.00O12, and Li4.53Ga0.72La2.94Zr1.98O12. The NMR spectra are interpreted as indicating that Ga(3+) mainly occurs in a distorted 4-fold coordinated environment that probably corresponds to the general 96h crystallographic site of garnet.
authors.affiliation: Department of Materials Science and Physics, University of Salzburg , Hellbrunnerstrasse 34, A-5020 Salzburg, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rettenwander
authors.forename: Charles A
authors.initials: CA
authors.lastname: Geiger
authors.forename: Martina
authors.initials: M
authors.lastname: Tribus
authors.forename: Peter
authors.initials: P
authors.lastname: Tropper
authors.forename: Georg
authors.initials: G
authors.lastname: Amthauer