The effect of cycle deformation on the AC conductivity of (Bi0.3Sb0.7)2Te3 films

It has been found that the resistance of the (Bi_0.3Sb_0.7)₂Te₃ porous polycrystalline film fabricated by thermal vacuum evaporation at substrate temperature T _s ≤ 363 K drastically decreases near the threshold AC frequency ω₀ ≈ 10⁵ Hz as low as the resistance of dense films with T _s ≈ 423 K. After the action of N ≈ 10⁵ cycles of mechanical deformation with amplitude ε = ±1 × 10^–3 a.u., the film resistance increases by 1.5 times and the threshold frequency decreases in almost 10² times, which can qualitatively be accounted for by the model of microcontacting blocks.