Single-crystal neutron diffraction on gamma-LiAlO2: structure determination and estimation of lithium diffusion pathway

Wiedemann, Dennis; Indris, Sylvio; Meven, Martin; Pedersen, Björn; Boysen, Hans; Uecker, Reinhard; Heitjans, Paul und Lerch, Martin (2016): Single-crystal neutron diffraction on gamma-LiAlO2: structure determination and estimation of lithium diffusion pathway. In: Zeitschrift für Kristallographie-Crystalline Materials, Bd. 231, Nr. 3: S. 189-193

Abstract

gamma-Lithium aluminum oxide is a paradigmatic example of an ultraslow lithium ion conductor. This characteristic plays a crucial role in its proposed and actual applications. Herein, we report on the outcome of single-crystal neutron diffraction studies at ambient and high temperature. Careful evaluation confirms the commonly assumed room-temperature structure as derived by powder neutron diffraction in 1965. At 1043 K, a split of the lithium position hints at the onset of intrinsic diffusion. Analysis of the negative scattering-length density using the maximum-entropy method (MEM) indicates a preference for a strongly curved diffusion pathway traversing octahedral voids between adjacent lithium sites. These results help to understand ultraslow lithium diffusion in well-ordered ionic solids on the microscopic scale and, ultimately, to establish structure-property relationships.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Geowissenschaften > Department für Geo- und Umweltwissenschaften
• Themengebiete: 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie
• ISSN: 2194-4946
• Sprache: Englisch