Energy spectrum of (Sn0.65Pb0.35)(0.95)Ge0.05Te solid solutions

The paper reports the study on the resistivity rho and thermoemf S of the ( Sn0.65Pb0.35)(0.95)Ge0.05Te solid solution layers. The dependences of rho a nd S on the hole concentrations in the range 3 x 10(19)-2 x 10(21) cm(-3) e xhibit jumps in the resistivity and thermoemf minima at close hole concentr ations p(1) approximate to 9 x 10(19) cm(-3), p(2) approximate to 2.5 x 10( 20) cm(-3), and p(3) approximate to 4.5 x 10(20) cm(-3). The observed jumps and minima suggest a complex structure of the valence band and the presenc e of critical points in the energy spectrum of holes. According to the data for SnTe, the critical points in the energy spectrum at the given hole con centrations are identified as the Sigma-extremum, saddle point L Sigma, and Delta-extremum, respectively. (C) 2000 MAIK "Nauka/Interperiodica".