Single-crystal neutron and X-ray diffraction study of garnet-type solid-state electrolyte Li6La3ZrTaO12: an in situ temperature-dependence investigation (2.5 ≤ T ≤ 873 K)

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials, vol. 77, pp. 123–130

Abstract

Large single crystals of garnet-type Li6La3ZrTaO12 (LLZTO) were grown by the Czochralski method and analysed using neutron diffraction between 2.5 and 873 K in order to fully characterize the Li atom distribution, and possible Li ion mobility in this class of potential candidates for solid-state electrolyte battery material. LLZTO retains its cubic symmetry (space group Ia 3 d) over the complete temperature range. When compared to other sites, the octahedral sites behave as the most rigid unit and show the smallest increase in atomic displacement parameters and bond length. The La and Li sites show similar thermal expansion in their bond lengths with temperature, and the anisotropic and equivalent atomic displacement parameters exhibit a distinctly larger increase at temperatures above 400 K. Detailed inspection of nuclear densities at the Li1 site reveal a small but significant displacement from the 24d position to the typical 96h position, which cannot, however, be resolved from the single-crystal X-ray diffraction data. The site occupation of LiI ions on Li1 and Li2 sites remains constant, so there is no change in site occupation with temperature.

Authors 5

1. Günther Josef Redhammer

   University of Salzburg

   Affiliation as printed

   Department of Chemistry and Physics of Materials, Division of Materials Science and Mineralogy, University of Salzburg, Jakob-Haringerstr. 2A, Salzburg, 5020, Austria

   Department of Chemistry and Physics of Materials, Division of Materials Science and Mineralogy, University of Salzburg, Jakob-Haringerstr. 2A, Salzburg, 5020, Austria,

2. Martin Meven Aachen Institute of Crystallography

   Forschungszentrum Jülich · Heinz Maier-Leibnitz Zentrum · RWTH Aachen University

   Affiliation as printed

   Institute of Crystallography, RWTH Aachen University, Jaegerstrasse 17/19, Aachen, 52056, Germany

   Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstrasse 1, Garching, 85748, Germany

   Institute of Crystallography, RWTH Aachen University, Jaegerstrasse 17/ 19, Aachen, 52056, Germany,

   Ju ¨lich Centre for Neutron Science (JCNS), Forschungszentrum Ju ¨lich GmbH at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstrasse 1, Garching, 85748, Germany,

3. Steffen Ganschow

   Leibniz Institute for Crystal Growth

   Affiliation as printed

   Leibniz-Institut für Kristallzüchtung (IKZ), Max-Born-Strasse 2, Berlin, 12489, Germany

   Leibniz-Institut fu ¨r Kristallzu ¨chtung (IKZ), Max-Born-Strasse 2, Berlin, 12489, Germany, and

4. Gerold Tippelt

   University of Salzburg

   Affiliation as printed

   Department of Chemistry and Physics of Materials, Division of Materials Science and Mineralogy, University of Salzburg, Jakob-Haringerstr. 2A, Salzburg, 5020, Austria

   Department of Chemistry and Physics of Materials, Division of Materials Science and Mineralogy, University of Salzburg, Jakob-Haringerstr. 2A, Salzburg, 5020, Austria,

5. Daniel Rettenwander corresponding

   Graz University of Technology

   Affiliation as printed

   Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, Graz, 8010, Austria