Microstructure and thermoelectric properties of extruded n-type 95%Bi2Te2-5%Bi2Se3 alloy along bar length

n-Type SbI3-doped 95%Bi2Te3-5%Bi2Se3 Compounds were prepared by a gas atomization and extrusion at 450 degreesC in the ratio 25:1. The dynamic recrystallization and thermoelectric properties of the compounds along extruded bar were investigated by a combination of microscopy, XRD and thermoelectric property testing. The microstructure of extruded bar shows homogeneous and fine distribution through full length due to dynamic recrystallizaiton during hot extrusion. The Seebeck coefficient at extruded bar length of 70 min is 160 muV K-1 and with increasing extruded bar length to 260 and 780 mm, the Seebeck coefficient is 150 and 154 muV K-1, respectively. The electrical resistivity of 70 min bar length is about 0.677 x 10(-5) Omegam and with increasing the length to 260 and 780 mm, the value is 0.510 and 0.587 x 10(-5) Omegam. (C) 2003 Elsevier Science B.V. All rights reserved.