Resonant impurity states in PbTe-based alloys doped with gallium and chromium under pressure

The galvanomagnetic effects in the n-Pb1-xSnxTe:Ga (x=0.21) and n-Pb1-yGeyTe:Cr (y=0.10) alloys at temperatures 4.2≤T≤300 K and under hydrostatic compression up to 17 kbar have been investigated. It is found that in almost the whole investigated pressure range in the samples investigated temperature dependencies of resistivity and Hall coefficient have a ''metallic'' character, indicating stabilization of the Fermi level by the impurity resonant levels. Using the experimental data in the framework of a two-band Kane dispersion law the dependencies of the free electron concentration and the Fermi-level position upon the pressure were calculated. The pressure coefficients of gallium and chromium deep-level movement were obtained and the models of the electronic-structure reconstruction under pressure were developed. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)