Effect of scandium doping and of matrix composition variation on galvanomagnetic properties and electronic structure of Pb1-x-ySnxScyTe alloys

Abstract

We synthesize a single-crystal Pb1-x-ySnxScyTe (x = 0.08, y = 0.02) ingot and investigate the composition and the galvanomagnetic properties of samples cut from it. We find that all samples are single-phase and determine the distribution of tin and scandium along the ingot. As the concentration of scandium increases, we find the p-n-inversion of the conductivity type at the liquid-helium temperature, an increase in the electron concentration, and its saturation at n ≈ 1.0 × 1020 cm−3, indicating the pinning of the Fermi level by the scandium resonant level located well above the bottom of the conduction band. Using the six-band Dimmock dispersion relation, dependences of the Fermi energy on the scandium and tin content are calculated. A diagram of the electronic structure rearrangement of Pb1-x-ySnxScyTe upon increasing tin content is proposed; the energy and the compositional coefficient of the scandium level movement with respect to the band edges are estimated.