Boron interaction with D03 phase in Fe-(27–29)Ga alloys

Abstract Two Fe–Ga alloys with 27 and 29% Ga additionally alloyed with boron (B) were studied using neutron diffraction, scanning electron microscopy with energy dispersive spectroscopy, and magnetostriction measurements. Neutron diffraction experiments demonstrated that the preponderant phase is the cubic Fe3Ga with structure D03. The lattice parameter of the Fe3Ga phase is much larger than the expected if the Ga composition of this phase is considered. The conclusion is that boron enters in the interstitial octahedral sites of the D03 lattice causing the lattice expansion, whose result is supported by ab initio calculations. Consequently, an increase on the magnetostriction is attributed to B located at the interstices that introduces local strains in the lattice. It is also suggested that the expansion of the lattice may increase Ga solubility in the D03 phase.