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Vol.43, No.1, 74 ~ 80, 2005
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| Title |
| The Influence of Extrusion Ratio on Microstructures and Thermoelectric Properties of Rapidly Solidified N-type Bi2Te2.75Se0.15 Thermoelectric Materials |
| 김태경 Tae Kyung Kim , 이상일 Sang Il Lee , 임종호 Jong Ho Lim , 손현택 Hyeon Taek Son , 김택수 Taek Soo Kim , 천병선 Byong Sun Chun |
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| Abstract |
| The n-Type thermoelectric compounds of Bi₂Te_(2.75)Se_(0.15) doped with 0.1 wt% SbI₃ were fabricated by gas atomization process and extruded under ratio of 16:1 and 28:1 at 450℃. The effect of extrusion ratio on the microstructures and thermoelectric properties were investigated by a combination of microscopy, XRD and thermoelectric properties. Grains of extruded bars are smaller than those of heated powder at extrusion temperature (450℃) due to the dynamic recrystallization but with increasing the amount of plastic deformation, grains of specimen extruded with 28:1 were slightly coarse. The compressive strength of hot extruded bar under 28:1 is 160 MPa and with decreasing the extrusion ratio to 16:1, the value is 250 MPa. The Seebeck coefficient a and electrical resistivity p were decreased with increasing ratio, while thermal conductivity x was increased. this results from decrease of carrier scattering and increase of carrier mobility. Extruded bar under ratio of 16:1 shows the higher value of figure of merit (Z=2.50x10^(-3)/K) than that of 28:1 (Z=2.07x10^(-3)/K). (Received June 24, 2004) |
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| Key Words |
| Thermoelectric properties, Extrusion ratio, Compressive strength, Bi2Te2.75Se0.15 |
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