Measuring current effect on low-temperature resistivity of n-type Bi1.9Lu0.1Te3 compound: Probing the changing in conductivity mechanism under weak electric field

The measuring current effect on low-temperature resistivity of Bi1.9Lu0.1Te3 has been analyzed. Values of currents correspond to weak electric fields with strength of several V·m−1. Temperature behavior of the resistivity is connected to two mechanisms. High-temperature mechanism (above 35 K) is due to acoustic phonon scattering. For this mechanism, the resistivity is growing with both increasing temperature and increasing current (positive current effect). Low-temperature mechanism (below 35 K) results in appearance of resistivity minimum at low temperatures. Below the minimum, the resistivity is growing with decreasing temperature. This feature is originated from contribution from variable-range hopping conductivity. With increasing current, the resistivity is falling (negative current effect). Crossover from positive to negative current effect on the resistivity occurs with decreasing temperature. Positive effect is originated from saturation of drift velocity of electrons under electric field. Negative effect is due to activation of hopping conductivity via electric field. •Measuring current effect on low-temperature resistivity of Bi1.9Lu0.1Te3 was studied.•Values of currents corresponds to weak electric fields with strength of several V·m-1.•Acoustic phonon scattering is high-temperature mechanism (>~35 K) of conductivity.•Variable-range hopping conductivity is low-temperature mechanism of conductivity.•Sign of current effect (positive or negative) is dependent on conductivity mechanism.