| 학회 |
한국재료학회 |
| 학술대회 |
2014년 봄 (05/15 ~ 05/16, 창원컨벤션센터) |
| 권호 |
20권 1호 |
| 발표분야 |
A. 전자/반도체 재료(Electronic and Semiconductor Materials) |
| 제목 |
Effect of high energy milling process on the thermoelectric properties of La doped SrTiO3 ceramics |
| 초록 |
In this paper, La doped SrTiO3 ceramics were prepared by high-energy milling process and compared with the conventional ball milling process. In order to obtain a nano-sized particle, the starting materials were mixed and the calcined powders were milled using a high-energy milling machine. This new manufacturing technique improves the reaction condition and also allows the processing of dense ceramics at low temperature. Another purpose of this study is to investigate the effects of La doping, as a function of sintering temperature on the microstructure and thermoelectric properties of SrTiO3 ceramics. Analytical grade raw materials of SrCO3, TiO2 and La2O3 were weighted and high-energy nano milled using ethanol as a solvent. The powder was calcined at 1173 K for 6 hours in air atmosphere. X-ray diffraction analysis at this stage indicated a single perovskite phase for doped and un-doped samples. The calcined powders were then compacted into disks of 15 mm diameter and a rectangular columns of (10 mm × 3 mm × 3 mm), followed by normal sintering between 1450 K and 1650 K for 4 h in forming gas (4 vol.% hydrogen in argon) for measurement of Seebeck coefficient and electrical conductivity. The micro-structural analysis revealed that, the high-energy milling process improved the reaction activity and homogeneity of the materials used throughout the process, accompanying the enhancement of the sintering density, grain uniformity, and the decrease of grain size. The Seebeck coefficient and electrical conductivity were measured at 303 K to 973 K using ZEMⅢ system. The thermal conductivity was calculated from the product of thermal diffusivity (D), specific heat (Cp), and density (d). The present work revealed that high-energy milling process is beneficial to improve the thermoelectric properties of La doped SrTiO3. |
| 저자 |
Hae-Jun Lee1, Iqbal Mahmud2, Man-Soon Yoon1, Soon-Chul Ur2
|
| 소속 |
1Department of Materials Science and Engineering, 2Korea National Univ. of Transportation |
| 키워드 |
High-energy milling; SrTiO₃; Thermoelectric; sintering
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| E-Mail |
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