Investigations on a two‐valence band model for Sb 2 Te 3

A two‐valence band model with a single‐and six‐valley structure is developed for the interpretation of galvanomagnetic effects in p‐type mixed crystals of the system (Bi x Sb 1− x ) 2 Te 3 (0 ≦ x ≦ 1), especially for x = 0 under the assumption of a purely anisotropic scattering in each band, neglecting interband and intervalley scattering. This model, refering to results from Shubnikov‐de Haas investigations on Sb 2 Te 3 at 4 K, is tested with galvanomagnetic data of undoped Sb 2 Te 3 in the temperature region 100 K ≦ T ≦ 360 K. It is, however, not possible to fit such a two‐valence band model to these data sufficiently well due, possibly, of a more complicated scattering process of charge carriers.