Galvanomagnetic properties and electronic structure of Pb1−x−ySnxVyTe under pressure

We study the galvanomagnetic properties in weak magnetic fields (4.2 ≤ T ≤ 300 K, B ≤ 0.07 T) and the Shubnikov-de Haas effect (T = 4.2 K, B ≤ 7 T) in single crystal Pb1−x−ySnxVyTe alloys under variation of alloy composition (x = 0.05–0.20, y ≤ 0.01) and hydrostatic compression up to 15 kbar. The increase of vanadium impurity content leads to the p-n-conversion and to a transition in the insulating phase due to the pinning of Fermi level by the donor-type deep vanadium impurity level situated under the bottom of the conduction band. We found that pressure induces a decrease of the activation energy of the vanadium level, the n-p-inversion of the conductivity type at low temperatures and an insulator–metal transition. In the metallic phase, a sharp increase of the Hall mobility (up to 3 × 105 cm2 V−1 s−1) and appearance of Shubnikov-de Haas oscillations are observed at helium temperature. The pressure and temperature coefficients of vanadium deep level energy are determined, and the diagram of the electronic structure rearrangement for Pb1−x−ySnxVyTe under pressure is proposed. (paper)