Fermi level tuning and weak localization/weak antilocalization competition of bulk single crystalline Bi2−xSbxSe2Te compounds

Publisher： IOP Publishing

E-ISSN： 1361-648X|27|2|25502-25507

ISSN： 0953-8984

Source： Journal of Physics: Condensed Matter, Vol.27, Iss.2, 2015-01, pp. : 25502-25507

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Abstract

From the investigation of the electrical transport properties of single crystalline Bi2−xSbxSe2Te (x = 0.0, 0.6, 0.8, 1.0, 1.2 and 1.4) compounds, we observed a systematic change of the Fermi level from n-type metallic (x = 0.0 and 0.6) or small-gap semiconducting (x = 0.8) to p-type semiconducting (x = 1.0) and metallic (x = 1.2 and 1.4), respectively, with increasing Sb-substitution concentration based on temperature-dependent electrical resistivity ρ(T) and Hall resistivity ρxy(H) measurements, respectively. The parent compound Bi2Se2Te exhibits linear negative magnetoresistance at low magnetic fields (H 1 T) by weak localization. The intermediate doped compounds of x = 0.8 and 1.0 showed weak antilocalization (WAL) and weak localization (WL) crossover behavior from the field-dependent magnetoresistance measurements at low temperatures. From the Hikami–Larkin–Nagaoka analysis of the compounds (x = 0.8 and 1.0), we found that there is a competing behavior between WL and WAL in terms of Sb-doping and magnetic field strength.