中国物理B ›› 2016, Vol. 25 ›› Issue (3): 38103-038103.doi: 10.1088/1674-1056/25/3/038103

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Unifying the crystallization behavior of hexagonal and square crystals with the phase-field-crystal model

Tao Yang(杨 涛), Zheng Chen(陈铮), Jing Zhang(张静), Yongxin Wang(王永新), Yanli Lu(卢艳丽)   

  1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China
  • 收稿日期:2015-09-07 修回日期:2015-11-13 出版日期:2016-03-05 发布日期:2016-03-05
  • 通讯作者: Tao Yang E-mail:420929211@163.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 54175378, 51474176, and 51274167), the Natural Science Foundation of Shaanxi Province, China (Grant No. 2014JM7261), and the Doctoral Foundation Program of Ministry of China (Grant No. 20136102120021).

Unifying the crystallization behavior of hexagonal and square crystals with the phase-field-crystal model

Tao Yang(杨 涛), Zheng Chen(陈铮), Jing Zhang(张静), Yongxin Wang(王永新), Yanli Lu(卢艳丽)   

  1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China
  • Received:2015-09-07 Revised:2015-11-13 Online:2016-03-05 Published:2016-03-05
  • Contact: Tao Yang E-mail:420929211@163.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 54175378, 51474176, and 51274167), the Natural Science Foundation of Shaanxi Province, China (Grant No. 2014JM7261), and the Doctoral Foundation Program of Ministry of China (Grant No. 20136102120021).

摘要: By employing the phase-field-crystal models, the atomic crystallization process of hexagonal and square crystals is investigated with the emphasis on the growth mechanism and morphological change. A unified regime describing the crystallization behavior of both crystals is obtained with the thermodynamic driving force varying. By increasing the driving force, both crystals (in the steady-state) transform from a faceted polygon to an apex-bulged polygon, and then into a symmetric dendrite. For the faceted polygon, the interface advances by a layer-by-layer (LL) mode while for the apex-bulged polygonal and the dendritic crystals, it first adopts the LL mode and then transits into the multi-layer (ML) mode in the later stage. In particular, a shift of the nucleation sites from the face center to the area around the crystal tips is detected in the early growth stage of both crystals and is rationalized in terms of the relation between the crystal size and the driving force distribution. Finally, a parameter characterizing the complex shape change of square crystal is introduced.

关键词: dendrite, faceted polygon, phase-field-crystal model

Abstract: By employing the phase-field-crystal models, the atomic crystallization process of hexagonal and square crystals is investigated with the emphasis on the growth mechanism and morphological change. A unified regime describing the crystallization behavior of both crystals is obtained with the thermodynamic driving force varying. By increasing the driving force, both crystals (in the steady-state) transform from a faceted polygon to an apex-bulged polygon, and then into a symmetric dendrite. For the faceted polygon, the interface advances by a layer-by-layer (LL) mode while for the apex-bulged polygonal and the dendritic crystals, it first adopts the LL mode and then transits into the multi-layer (ML) mode in the later stage. In particular, a shift of the nucleation sites from the face center to the area around the crystal tips is detected in the early growth stage of both crystals and is rationalized in terms of the relation between the crystal size and the driving force distribution. Finally, a parameter characterizing the complex shape change of square crystal is introduced.

Key words: dendrite, faceted polygon, phase-field-crystal model

中图分类号:  (Growth from melts; zone melting and refining)

  • 81.10.Fq
64.70.dg (Crystallization of specific substances) 61.50.Ah (Theory of crystal structure, crystal symmetry; calculations and modeling) 07.05.Tp (Computer modeling and simulation)