Influence of Deformation on Pb_1−xIn_xTe_1−yI_y and Pbx_1−−ySn_xIn_yTe Films

Herein, the original technique for transport measurements at one-axis deformation is applied for the characterization of In-doped n-type Pb_1−xSn_xTe thin films on a mica substrate. The main advantage of the developed setup is the possibility of obtaining a significantly higher pressure compared with bulk samples. A systematic study of the transport properties as a function of pressure for In-doped PbTe and PbSnTe films is conducted. A huge deformation of up to ≈6% without sample destruction is obtained within one-axis deformation and an applied pressure of up to ≈30 kbar for Pb_1−xIn_xTe_1−yI_y and Pb_1−x−ySn_xIn_yTe thin films. This allowed us to determine the position of the In resonance level in the band spectrum of the PbSnTe compound as a function of the pressure. The In impurity level is moving up with the application of pressure. Such a conclusion is confirmed by the Hall effect and electrical conductivity measurements for Pb_1−xSn_xTe films doped with In and can be explained by the fact that In impurity wave functions are strongly localized and interact weakly with Bloch states of PbSnTe and with each other.