Atomic structure solution of the complex quasicrystal approximant Al77Rh15Ru8 from electron diffraction data. Issue 6 (1st December 2014)

• Record Type: Journal Article
• Authors: Samuha, Shmuel; Mugnaioli, Enrico; Grushko, Benjamin; Kolb, Ute; Meshi, Louisa
• Is Part Of: Acta crystallographica. Volume 70:Issue 6(2014:Dec.)
• Page Start: 999
• Page End: 1005
• Publication Date: 2014-12-01
• DOI: 10.1107/S2052520614022033
• Languages: English
• ISSNs: 2052-5206

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>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 [<italic>Pbma</italic>, <italic>a</italic> = 23.40 (5), <italic>b</italic> = 16.20 (4) and <italic>c</italic> = 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.</p> </abstract>