Non-conservative dynamics of lattice sites near a migrating interface in a diffusional phase transformation. (1st April 2017)

• Record Type: Journal Article
• Authors: Yang, T.; Gao, Y.; Wang, D.; Shi, R.P.; Chen, Z.; Nie, J.F.; Li, J.; Wang, Y.
• Is Part Of: Acta materialia. Volume 127(2017)
• Page Start: 481
• Page End: 490
• Publication Date: 2017-04-01
• Subjects: Non-conservative dynamics -- Structural ledge -- Growth ledge -- Lattice correspondence -- Phase field crystal model; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2017.01.036
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Migration of phase boundaries in crystalline solids eliminates one set of lattice sites and establishes another. Using a combination of phase field crystal modeling and crystallographic analysis, we present here a complete atomistic description of the migration mechanism of a high-index planar interface during a diffusional hexagon to square phase transformation. In particular we show that a terrace-step interface advances macroscopically in the form of growth ledges, while microscopically its migration occurs by opposite shearing on the terraces and a one-to-two splitting of lattice sites, giving a new class of lattice site correspondence and superabundant vacancies. In addition, a new approach capable of finding a critical nucleus with atomic resolution is developed by combining the phase field crystal energetics with the free-end nudged elastic band algorithm. Graphical abstract: Image 1