Berlin 2024 – wissenschaftliches Programm
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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur
KFM 32: Crystal Structure Defects / Real Structure / Microstructure II
KFM 32.5: Vortrag
Freitag, 22. März 2024, 11:00–11:20, E 124
Amplitude phase-field quasicrystal — •Marcello De Donno1, Marco Salvalaglio1,2, Luiza Angheluta3, and Ken Elder4 — 1Institute of Scientific Computing, TU Dresden, 01062 Dresden, Germany — 2Dresden Center for Computational Materials Science, TU Dresden, 01062 Dresden, Germany — 3Njord Centre, Department of Physics, University of Oslo, 0371 Oslo, Norway — 4Department of Physics, Oakland University, Rochester, Michigan 48309, USA
Quasicrystals challenge classical crystallography with their atypical atomic arrangements, characterized by a lack of periodicity while retaining long-range order. They represent a unique state of matter, lying between crystalline and amorphous structures. Since their discovery in 1982, quasicrystals have been shown to be capable of improving the mechanical properties of alloys, offering heightened strength, hardness, and resistance to wear. Additionally, their propensity for low friction makes them excellent candidates for coatings aimed at diminishing wear in moving parts.
The study of quasicrystals requires understanding the interaction between the exotic microscopic arrangement and the macroscopic properties of the material. We propose a novel mesoscale theory for quasicrystals, taking advantage of an extension we designed to the amplitude phase-field crystal model. We characterize the topological defects forming in the structure, and we discuss their kinematics. Finally, we derive self-consistent laws for linear elasticity in the quasicrystal.
Keywords: Quasicrystal; Phase-field crystal; Dislocation dynamics; Crystal plasticity; Ginzburg-Landau theory