First Principles Study on Elastic Constants, Ferromagnetism and Electronic Structures of Alloyed Fe₃Si Doped with Mo, Ti or Nb

Elastic constants, ferromagnetism and electronic structures of Fe₁₁MoSi₄, Fe₁₁TiSi₄, and Fe₁₁NbSi₄ are studied by first-principles calculations with density functional theory (DFT). It is found that the ductility of Fe₃Si could be obviously improved with the addition of Ti. The G/B₀ of Fe₁₁TiSi₄ is 0.483, which means that it is ductile. The strong interaction of Fe 3d–Ti 3d intensifies the metallic character. However, Fe₁₁NbSi₄ has the optimal ferromagnetism. The total magnetic moments of the Fe₁₁NbSi₄ is 20.42μ_B. The difference between spin-up electrons and spin-down electrons at the Fermi level markedly varies with different alloying elements; furthermore, the difference at E_F in the Nb case is the highest.