Quantifying a two-mode phase-field crystal model for BCC metals at melting point

A recently developed two-mode phase-field crystal (PFC) model (Wu et al., 2010; Asadi and Asle Zaeem, 2015) is applied for quantitative modeling of body centered cubic (BCC) crystals at their melting points. This model incorporates the first two density wave vectors of BCC crystals in its formulation and consists of three model parameters (two independent and one dependent) in its dimensionless form. A systematic study is presented to show that the two independent parameters of the model control the material properties such as solid and liquid densities and the structure factor. An iterative procedure is presented to determine the PFC model parameters for specific BCC materials using their liquid structure factor and the fluctuation amplitude of atoms in their crystalline state. As a case study, the two-mode PFC model parameters are determined for Fe at its melting point. The calculated model parameters and results of the PFC model are validated by comparing the calculated expansion in melting, solid and liquid densities, elastic constants, and bulk modulus of Fe with the available experimental and computational data in the literature. In addition, to show the potential application of this PFC model, the solid-liquid interface free energy and surface anisotropy of Fe are determined and compared with their available counterparts in the literature. (C) 2015 Elsevier B.V. All rights reserved.