First principles study on the structural, magnetic and electronic properties of Te-doped BiF3

The structural, magnetic and electronic properties of Te-doped BiF3 were investigated by first-principles calculations in this paper. We focused on TexBi1−xF3 systems, in which x is equal to 0, 3.125 atom%, 6.25 atom%, 12.5 atom% and 25 atom% of Te doping concentration, respectively. The formation energy analysis indicates that the difficulty of Te doping BiF3 decreases with the increase of Te doping concentration, and Te doping BiF3 is much easier in the F-rich conditions than in the Bi-rich conditions. Besides, the calculated cohesive energy of Te doping BiF3 shows that the stability of Te doped BiF3 becomes worse with the increase of Te doping concentration. What is more, Te doped BiF3 shows obvious magnetic character. As for electronic properties of Te-doped BiF3, the results show that the band gap of TexBi1−xF3 decreases with the increase of Te doping concentration. For TeBi3F12, TeBi7F24 and TeBi15F48, Fermi level shifts into the spin-up conductivity band while spin-down energy band has a band gap at Fermi level, and thus the compounds exhibit half metallic characters with good conductivity when Te atoms substitute partly Bi atoms.