Crystallization induced by multiple seeds: Dynamical density functional approach

Neuhaus, Tim; Schmiedeberg, Michael; Löwen, Hartmut

doi:10.1103/physreve.88.062316

Cited by 11 publications

(15 citation statements)

References 49 publications

(61 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Future work should focus on more detailed models of quasicrystal growth. One option is to go for dynamical density functional theory [39,51], which is a more microscopic description for the particle interaction than the phase-field crystal model considered here. To obtain stable quasicrystals, one either needs a complex effective interaction in a onecomponent system or binary systems.…”

Section: Discussionmentioning

confidence: 99%

“…For each angle the distance d between seeds is varied. A similar setup for the growth of periodic structures was studied by using density functional theory [39,47].…”

Section: B Setupmentioning

confidence: 99%

“…For quasicrystals, the same basic question is relevant, e.g., if these are grown from liquid metallic alloys [37,38]: Is it possible to grow perfect quasicrystals, i.e., structures without domain borders once several nucleation centers are present? For the case of a periodic crystal grown from two seeds, we observed [39] that if the orientation of the two seeds is similar, or they are close together, then the growth might result in a monocrystal, while if the seeds are far away from each other and rotated with respect to each other, then they grow into two stable crystals that form a domain boundary in between. Here we explore the growth of a quasicrystal from two seeds and explain that there is the possibility to excite phasonic strain, which suppresses the dislocations if the seeds are not too far apart from each other.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Dislocation-free growth of quasicrystals from two seeds due to additional phasonic degrees of freedom

et al. 2017

Self Cite

View full text Add to dashboard Cite

We explore the growth of two-dimensional quasicrystals, i.e., aperiodic structures that possess long-range order, from two seeds at various distances and with different orientations by using dynamical phase-field crystal calculations. We compare the results to the growth of periodic crystals from two seeds. There, a domain border consisting of dislocations is observed in case of large distances between the seed and large angles between their orientation. Furthermore, a domain border is found if the seeds are placed at a distance that does not fit to the periodic lattice. In the case of the growth of quasicrystals, we only observe domain borders for large distances and different orientations. Note that all distances do inherently not match to a perfect domain wall-free quasicrystalline structure. Nevertheless, we find dislocation-free growth for all seeds at a small enough distance and for all seeds that approximately have the same orientation. In periodic structures, the stress that occurs due to incommensurate distances between the seeds results in phononic strain fields or, in the case of too large stresses, in dislocations. In contrast, in quasicrystals an additional phasonic strain field can occur and suppress dislocations. Phasons are additional degrees of freedom that are unique to quasicrystals. As a consequence, the additional phasonic strain field helps to distribute the stress and facilitates the growth of dislocation-free quasicrystals from multiple seeds. In contrast, in the periodic case the growth from multiple seeds most likely leads to a structure with multiple domains. Our work lays the theoretical foundations for growing perfect quasicrystals from different seeds and is therefore relevant for many applications.

show abstract

Section: Discussionmentioning

confidence: 99%

“…For each angle the distance d between seeds is varied. A similar setup for the growth of periodic structures was studied by using density functional theory [39,47].…”

Section: B Setupmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dislocation-free growth of quasicrystals from two seeds due to additional phasonic degrees of freedom

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…In a two-dimensional system, the growth of the crystalline phase in the presence of two seeds had been investigated within density functional theory, revealing that the relative orientation of the seeds is an additional factor that controls the properties of the final phase. 32 …”

Section: Introductionmentioning

confidence: 99%

Heterogeneous Crystallization on Pairs of Pre-Structured Seeds

Jungblut

Dellago

2016

J. Phys. Chem. B

View full text Add to dashboard Cite

Studying the effects of small pre-structured seeds on the crystallization transition in an undercooled monodisperse Lennard-Jones fluid with transition interface path sampling combined with molecular dynamics simulations, we analyze the impact of the simultaneous presence of two seeds with various structures. In the presence of seeds with face- and body-centered cubic structures, we find that decreasing the seed-to-seed distance enhances the probability of the crystalline clusters formed on one of the seeds to grow beyond the critical size, thus, increasing the crystal nucleation rates. In contrast, when seeds have an icosahedral structure, the crystalline clusters form mostly in the bulk. The crystal nucleation rate, however, is also determined by the distance between the seeds with regular structure in which the lattice spacing is equal to the bulk lattice constant, pointing to a heterogeneous crystal nucleation that occurs away from the icosahedrally structured seeds. For slightly squeezed seeds, the effects of the presence of seeds with face- and body-centered cubic structures are reduced in comparison to the regular seeds, and we do not see any effect of the presence of the second seed for seeds with squeezed icosahedral structure.

show abstract

“…By introducing small seeds with various structures into the undercooled liquid, one can modify the crystallisation mechanism by favouring the nucleation of particular arrangements and inhibiting the formation of others. Most of the previous studies on seeded crystallisation 31-38 considered either unstructured and rather large seeds [31][32][33][34][35] or twodimensional systems 37,38 . In three dimensions, Hermes et al 36 compared experimental results on crystallisation on small two-dimensional structured templates with computer simulations.…”

Section: Introductionmentioning

confidence: 99%

On the reaction coordinate for seeded crystallisation

Jungblut

Dellago

2015

Molecular Physics

View full text Add to dashboard Cite

Small pre-structured seeds introduced into an undercooled fluid are known to increase the crystal nucleation rate by some orders of magnitude, if the structure of the seeds is commensurate with the bulk crystalline phase. The presence of such seeds also alters the crystallisation mechanism by favouring particular structures at the early stages of the nucleation process. Here, we study with computer simulations the effect of small face-centred cubic and body-centred cubic seeds on the crystallisation of a Lennard-Jones liquid in the strongly undercooled regime. We find that seeds with body-centred cubic structure lead to a larger enhancement of the crystallisation rate than facecentred cubic seeds. An analysis of recurrence times reveals that the size of the largest crystalline cluster used as reaction coordinate is affected by pronounced memory effects, which depend on the particular seed structure and point to the importance of structural information in the definition of a good reaction coordinate for crystallisation.

show abstract

Crystallization induced by multiple seeds: Dynamical density functional approach

Cited by 11 publications

References 49 publications

Dislocation-free growth of quasicrystals from two seeds due to additional phasonic degrees of freedom

Dislocation-free growth of quasicrystals from two seeds due to additional phasonic degrees of freedom

Heterogeneous Crystallization on Pairs of Pre-Structured Seeds

On the reaction coordinate for seeded crystallisation

Contact Info

Product

Resources

About