Phase Field Crystal Study of Symmetric Tilt Grain Boundaries of Iron

We apply the phase field crystal model to study the structure and energy of symmetric tilt grain boundaries of bcc iron in 3D. The parameters for the model are obtained by using a recently developed eight-order fitting scheme [A. Jaatinen et al., Phys. Rev. B 80, 031602 (2009)]. The grain boundary free energies we obtain from the model are in good agreement with previous results from molecular dynamics simulations and experiments.

💡 Research Summary

The paper presents a comprehensive study of symmetric tilt grain boundaries (GBs) in body‑centered cubic (bcc) iron using the Phase‑Field Crystal (PFC) model, a continuum approach that retains atomic‑scale periodicity while allowing simulations over diffusive time scales. The authors first calibrate the PFC free‑energy functional for iron by employing the eight‑order fitting scheme introduced by Jaatinen et al. (Phys. Rev. B 80, 031602, 2009). This scheme simultaneously matches eight key material properties—lattice constant, three independent elastic constants (C11, C12, C44), the solid‑liquid coexistence temperature, the bulk modulus, the shear modulus, and the curvature of the free‑energy well—thereby producing a highly accurate representation of the bcc iron energy landscape.

With the calibrated functional, the authors construct a series of three‑dimensional bicrystal configurations containing symmetric tilt GBs about the