Structural, vibrational and electronic properties of D03 FeNi3

Abstract

The Fe-Ni invar alloys attract the great interest of researchers due to their anomalously low coefficient of thermal expansion for Fe-rich compositions and numerous technological and practical applications. The structural, vibrational and electronic properties of D03 FeNi3 studied using the first-principles plane wave self-consistent method with the Ultrasoft pseudopotential scheme under the framework of DFT. Calculated equilibrium lattice constant and isothermal bulk modulus for D03 FeNi3 presented with the other available results. Existence of imaginary phonon frequencies in the phonon dispersion curves of D03 FeNi3 suggest the dynamical instability of it. Significant contribution of d-electrons to the total electronic density of states is in agreement with the previously reported work. Electronic charge density plots for D03 FeNi3 predict weak metallic bonding between Fe and Ni compared to between Fe-Fe metal atoms. Fermi surface topology exhibit electron and/or hole character at different high symmetrical points of the Brillouin zone based on the crossing of bands at EF in the electronic band structure. Conclusions based on the phonon dispersion curves, phonon density of states, electronic band structure along with the total and projected density of states, electronic charge density and Fermi surface are summarized.