Marcello De Donno: Amplitude expansion of the phase-field crystal model for complex crystal structures

Vortragender/Speaker: Marcello De Donno
Ansprechpartner/Contact: Dr. Simon Praetorius
Videostream (BBB): https://tud.link/phf1

Titel/Title:
Amplitude expansion of the phase-field crystal model for complex crystal structures

Zusammenfassung/Abstract:
The phase field crystal model allows for studying phenomena on atomic length and diffusive time scales. It accounts for elastic and plastic deformation in crystals, including several processes such as crystal growth, dislocation dynamics, and microstructure evolution. The amplitude expansion of the phase field crystal model describes the atomic density by a small set of slowly-oscillating Fourier modes, making it possible to tackle large three-dimensional systems. However, only basic crystal symmetries have been studied so far. We present a general treatment of virtually any lattice symmetry using the amplitude phase field crystal model, incorporating approaches originally proposed for the phase field crystal model which enable the treatment of non-trivial lattices. We discuss the stability of selected crystal structures, focusing on non-Bravais lattices. As pivotal examples, we show that the proposed approach allows a coarse-grained description of the kagome lattice, exotic square arrangements, and the diamond lattice, hosting dislocations.