title: Atomic structure solution of the complex quasicrystal approximant Al77Rh15Ru8 from electron diffraction data.
abstract: The crystal structure of the novel Al77Rh15Ru8 phase (which is an approximant of decagonal quasicrystals) was determined using modern direct methods (MDM) applied to automated electron diffraction tomography (ADT) data. The Al77Rh15Ru8 E-phase is orthorhombic [Pbma, a = 23.40 (5), b = 16.20 (4) and c = 20.00 (5) Å] and has one of the most complicated intermetallic structures solved solely by electron diffraction methods. Its structural model consists of 78 unique atomic positions in the unit cell (19 Rh/Ru and 59 Al). Precession electron diffraction (PED) patterns and high-resolution electron microscopy (HRTEM) images were used for the validation of the proposed atomic model. The structure of the E-phase is described using hierarchical packing of polyhedra and a single type of tiling in the form of a parallelogram. Based on this description, the structure of the E-phase is compared with that of the ε6-phase formed in Al-Rh-Ru at close compositions.
authors.affiliation: Department of Materials Engineering, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.
authors.forename: Shmuel
authors.initials: S
authors.lastname: Samuha
authors.affiliation: Institut für Physikalische Chemie, Johannes Gutenberg-Universität Mainz, Welderweg 11, 55128 Mainz, Germany.
authors.forename: Enrico
authors.initials: E
authors.lastname: Mugnaioli
authors.affiliation: PGI-5, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Grushko
authors.affiliation: Institut für Physikalische Chemie, Johannes Gutenberg-Universität Mainz, Welderweg 11, 55128 Mainz, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Kolb
authors.affiliation: Department of Materials Engineering, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.
authors.forename: Louisa
authors.initials: L
authors.lastname: Meshi
keywords: electron diffraction tomography; icosahedral and decagonal quasicrystals; modern direct methods