Structural, magnetic and electronic properties of Fe-Ga-Tbx (0 ≤ x ≤ 1.85) alloys: Density-functional theory study

The structural, magnetic and electronic properties of Fe-Ga-Tbx (0 ≤x≤ 1.85) alloys have been studied by means of density functional theory. It was shown that the addition of Tb atoms into Fe–Ga alloy increases the lattice parameter and the magnetostriction. The largest value of tetragonal magnetostriction is observed for the composition Fe79.69Ga19.53Tb0.78 with a value of 596 ppm from the simulation. From the Density of States calcualtions, the increase in magnetostriction is attributed to the presence of nonbonding states around the Fermi level. The simulated Curie temperature of the studied compositions was in good agreement with the available experimental data. •Structural, magnetic and electric properties of Tb doped galfenol were studied by means of density functional theory.•The lattice parameter of the simulated alloys increased with the increase of Tb content.•All the studied compositions are mechanical stable.•Largest magnetostriction was observed for a Tb concentration of less than one atomic percent.•The splitting between t2g and eg orbitals play a crucial role in the appearance of magnetostriction.