Disordering in Fe3Ga alloy of D03 structure: Effect on stability and magnetostriction

Abstract

The effect of the structural disorder and Ga content variation on the mechanical stability and magnetostrictive properties of the Fe3Ga alloy of structure D03 was studied by density functional theory methods. There are contradictions between experimental data and simulation results for the compound under investigation. Calculations show that, in contrast to the experimental results, the magnetostriction coefficient should be negative. In addition, the energy-strain simulation predicts the mechanical instability of the perfect D03 lattice. Here it is demonstrated that the permutation of Fe and Ga atoms stabilizes the Fe–25Ga structure. However, the sign of the magnetostriction coefficient remains negative. The further structure modification by partially replacing Fe atoms with Ga leads to a change in the sign of the magnetostriction coefficient in agreement with the experiment.