The possibilities of magnetism induced by transition-metal atoms substitution in Bi2Te3 system are investigated by ab initio calculations. The calculated results indicate that a transition-metal atom substitution for a Bi atom produces magnetic moments, which are due to the spin-polarization of transition-metal 3d electrons. The values of magnetic moments are 0.92, 1.97, 2.97, 4.04, and 4.98 μB for 4% Ti-, V-, Cr-, Mn- and Fe-doped Bi2Te3 re- spectively. When substituting two transition-metal atoms, the characteristics of exchanging couple depend upon the distributions of the Bi atoms substituted. When two transition- metal atoms substituting for Bi atoms locate at the sites of Bil and Bi5, with the distance of 11.52A, the Bi1.84TM0.16Te3 system is energetically most stable and exhibits ferromagnetic coupling.
