Phase-field modeling for atoms*

Phase-field modeling has achieved great success in materials science to investigate, for example, crystallization, fracture, and ferroelectrics. However, phase-field modeling cannot be applied to atomic systems because they are based on continuum mechanics. In this talk, we will propose a phase-field modeling for atoms, in which an atom vibration is modelled as a Gauss distribution and their motion is calculated by the Cahn-Hilliard equation. Our methodology successfully reproduces a stabilization of the face-centered cubic structure of Cu metals under NVT and NPT ensembles. Furthermore, we will talk about our ongoing research, that is, we applied our methodology to ferroelectric materials, using a bond-valence interatomic potential of PbTiO3. We found that our methodology successfully reproduced the ferroelectric to paraelectric phase transition by the increment of temperature.