Scattering characteristics of grain boundaries in electrically sintered Bi0.4Sb1.6Te3 compounds

Electrical transport properties of grain boundaries in hot-pressed (HP) and electrically-sintered (ES) Bi0.4Sb1.6Te3 compounds are examined and interpreted based on the Mayadas-Shatzkes model. Both the HP and ES samples were pressed at 300 °C under a pressure of 110 MPa except an electric current of 260 A/cm2 was applied concurrently through the ES sample. The ES sample exhibits enhanced Hall mobility and increased carrier concentration while maintaining low lattice thermal conductivity. The improved carrier mobility is ascribed to the reduced reflection coefficient of grain boundaries in the slightly textured ES sample.