Energy spectrum of charge carriers in SmxPb1 − xTe

The electrical conductivity (σ), Hall coefficient ( R H , and thermopower (α) of Sm x Pb 1 − x Te have been measured at temperatures from 80 to 800 K. The results demonstrate that the Sm x Pb 1 − x Te solid solutions with x ≤ 0.04 are p -type semiconductors. We have determined the electron effective mass at the conduction band bottom ( m n = (0.031 ± 0.001) m 0 ) and Fermi level ( m * = (0.06 ± 0.001) m 0 ) and the hole effective mass ( m p = (0.34 ± 0.001) m 0 ). The temperature-dependent σ, R H , and α data are interpreted in terms of a model with two carrier types.