Possible evidence for topological surface states in nanocrystalline Bi2Te3

Bi2Te3 nanomaterials were grown by microwave synthesis technique. Resistivity of the material shows semiconducting like nature which has been interpreted by thermally activated behavior in the high temperature range, three dimensional variable range hopping (VRH) mechanism in the middle range and combined effect of both electron-electron interaction and weak antilocalization(WAL) in the lower temperature regime from 10K to 2K. Full cycle magnetoresistance (MR) at 2K of the material exhibits WAL effect that evolves smoothly in to a linear positive magneto resistance (LPMR) up to 10K, thereafter to a simple parabolic nature with respect to magnetic fields. These features unequivocally provide evidence for the so called topological surface states (TSS) in Bi2Te3 even in its nanocrystalline form.