Free energy calculation of Al-Cu-Fe quasicrystal phase with the effect of external potential

Based on Thomas-Fermi model, the change trend of free energy and Gibbs free energy of Al-Cu-Fe alloy and quasicrystal Al_62.5Cu₂₅ Fe_12.5 in electric field was calculated. The main conclusion is following: The stability of Al_62.5Cu₂₅Fe_12.5 phase in electric field is the lowest, and then is the compound Al₇Cu₂Fe, the binary compound Al₂Cu is more stable than quasicrystal phase and Al₇Cu₂Fe, but the stability of Al₂ Cu is lower than that of solid solution. With the effect of positive, negative boundary potential and electrode potential, the free energy of quasicrystal phase, compound and solid solution increase with the increasing of boundary potential and electrode potential, and the change trend is similar symmetry about zero, and the effect of positive electric field is more intensive than the negative electric field.