Nucleation and Post-Nucleation Growth in Diffusion-Controlled and Hydrodynamic Theory of Solidification
Two-step nucleation and subsequent growth processes were investigated in the framework of the single mode phase-field crystal model combined with diffusive dynamics (corresponding to colloid suspensions) and hydrodynamical density relaxation (simple liquids). It is found that independently of dynami...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-04-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/11/4/437 |
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| author | Frigyes Podmaniczky László Gránásy |
| author_facet | Frigyes Podmaniczky László Gránásy |
| author_sort | Frigyes Podmaniczky |
| collection | DOAJ |
| description | Two-step nucleation and subsequent growth processes were investigated in the framework of the single mode phase-field crystal model combined with diffusive dynamics (corresponding to colloid suspensions) and hydrodynamical density relaxation (simple liquids). It is found that independently of dynamics, nucleation starts with the formation of solid precursor clusters that consist of domains with noncrystalline ordering (ringlike projections are seen from certain angles), and regions that have amorphous structure. Using the average bond order parameter <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mover><mi>q</mi><mo>¯</mo></mover><mn>6</mn></msub></mrow></semantics></math></inline-formula>, we distinguished amorphous, medium range crystallike order (MRCO), and crystalline local orders. We show that crystallization to the stable body-centered cubic phase is preceded by the formation of a mixture of amorphous and MRCO structures. We have determined the time dependence of the phase composition of the forming solid state. We also investigated the time/size dependence of the growth rate for solidification. The bond order analysis indicates similar structural transitions during solidification in the case of diffusive and hydrodynamic density relaxation. |
| first_indexed | 2024-03-10T12:14:40Z |
| format | Article |
| id | doaj.art-9fcbe09fd8ff492ebf9039b33a4b2be4 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-03-10T12:14:40Z |
| publishDate | 2021-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-9fcbe09fd8ff492ebf9039b33a4b2be42023-11-21T15:59:10ZengMDPI AGCrystals2073-43522021-04-0111443710.3390/cryst11040437Nucleation and Post-Nucleation Growth in Diffusion-Controlled and Hydrodynamic Theory of SolidificationFrigyes Podmaniczky0László Gránásy1Wigner Research Centre for Physics, P.O. Box 49, H-1525 Budapest, HungaryWigner Research Centre for Physics, P.O. Box 49, H-1525 Budapest, HungaryTwo-step nucleation and subsequent growth processes were investigated in the framework of the single mode phase-field crystal model combined with diffusive dynamics (corresponding to colloid suspensions) and hydrodynamical density relaxation (simple liquids). It is found that independently of dynamics, nucleation starts with the formation of solid precursor clusters that consist of domains with noncrystalline ordering (ringlike projections are seen from certain angles), and regions that have amorphous structure. Using the average bond order parameter <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mover><mi>q</mi><mo>¯</mo></mover><mn>6</mn></msub></mrow></semantics></math></inline-formula>, we distinguished amorphous, medium range crystallike order (MRCO), and crystalline local orders. We show that crystallization to the stable body-centered cubic phase is preceded by the formation of a mixture of amorphous and MRCO structures. We have determined the time dependence of the phase composition of the forming solid state. We also investigated the time/size dependence of the growth rate for solidification. The bond order analysis indicates similar structural transitions during solidification in the case of diffusive and hydrodynamic density relaxation.https://www.mdpi.com/2073-4352/11/4/437classical density functional theorymolecular modellingtwo-step nucleationgrowth kineticshydrodynamic theory of freezing |
| spellingShingle | Frigyes Podmaniczky László Gránásy Nucleation and Post-Nucleation Growth in Diffusion-Controlled and Hydrodynamic Theory of Solidification Crystals classical density functional theory molecular modelling two-step nucleation growth kinetics hydrodynamic theory of freezing |
| title | Nucleation and Post-Nucleation Growth in Diffusion-Controlled and Hydrodynamic Theory of Solidification |
| title_full | Nucleation and Post-Nucleation Growth in Diffusion-Controlled and Hydrodynamic Theory of Solidification |
| title_fullStr | Nucleation and Post-Nucleation Growth in Diffusion-Controlled and Hydrodynamic Theory of Solidification |
| title_full_unstemmed | Nucleation and Post-Nucleation Growth in Diffusion-Controlled and Hydrodynamic Theory of Solidification |
| title_short | Nucleation and Post-Nucleation Growth in Diffusion-Controlled and Hydrodynamic Theory of Solidification |
| title_sort | nucleation and post nucleation growth in diffusion controlled and hydrodynamic theory of solidification |
| topic | classical density functional theory molecular modelling two-step nucleation growth kinetics hydrodynamic theory of freezing |
| url | https://www.mdpi.com/2073-4352/11/4/437 |
| work_keys_str_mv | AT frigyespodmaniczky nucleationandpostnucleationgrowthindiffusioncontrolledandhydrodynamictheoryofsolidification AT laszlogranasy nucleationandpostnucleationgrowthindiffusioncontrolledandhydrodynamictheoryofsolidification |