Study of α″-phase Fe16X2−nYn (X,Y = N, C) alloys by molecular dynamics modeling

Abstract

Atomic structures of α″-phase magnetic material C-doped Fe16N2−nCn [n = (0,2)] are investigated using molecular dynamics energy minimization method. Based on simulated annealing principles, a highly efficient search method is developed to find the approximation to “global” minimum energy states for these ternary bct lattice structures by sampling a series of local energy minimal from continuously divided minimization space. It is found that in Fe16N2−nCn alloy, although lattice parameters vary with C concentration, bond length rankings of C/N-Fe at Wyckoff positions are consistent with those in Fe16C2 and Fe16N2 phases. There are also existing Fe16N2−nCn alloys with high-C concentrations (C:N ≥ 1) showing higher stability than Fe16C2 and Fe16N2.