Galvanomagnetic Effects in p-Type Tellurium at Low Temperatures. I

Galvanomagnetic effects of p -type tellurium were investigated in the wide temperature range from 77 K to 0.05 K under magnetic fields up to 18 kOe. The samples were not intentionally doped and their carrier concentrations were ranging from 1.9 to 6.6×10 14 cm -3 . Anomalous behaviors in the temperature dependences of the conductivity and the Hall coefficient and in the magnetic field dependences of the Hall coefficient were observed below liquid helium temperatures. Furthermore these behaviors were different from those in slightly Sb-doped crystals. These could be explained by introducing a new kind of two-carrier model, in which the impurity band-like states exist below the top of the valence band. A role of lattice defects in forming the impurity band-like states was discussed in relation to the electronic structure of tellurium.