Atomic control of conductivity versus ferromagnetism in wide-gap oxides via selective doping: V, Nb, Ta in anatase TiO(2)

作者：Osorio Guillen Jorge^*; Lany Stephan; Zunger Alex

来源：Physical Review Letters, 2008, 100(3): 036601.

DOI：10.1103/PhysRevLett.100.036601

We identify two general types of electronic behaviors for transition-metal impurities that introduce excess electrons in oxides. (i) The dopants introduce resonant states inside the host conduction band and produce free electrons; (ii) the dopants introduce a deep gap state that carries a magnetic moment. By combining electronic structure calculations, thermodynamic simulations, and percolation theory, we quantify these behaviors for the case of column V-B dopants in anatase TiO(2). Showing behavior (i), Nb and Ta dopants can convert the insulator TiO(2) into a transparent conductor. Showing behavior (ii), V dopants could convert nonmagnetic TiO(2) into a ferromagnet. Whether a dopant shows behavior (i) or (ii) is encoded in its atomic d orbital energy.

• 出版日期2008-1-25