State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University
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DOI:
10.7502/j.issn.1674-3962.2016.01.09
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Abstract:
Yb-filled bulk CoSb3 skutterudites were prepared by melting method combining with Spark Plasma Sintering (SPS). Bulk Yb0.3Co4Sb12 compounds with superior thermoelectric properties（ZT=1.19,800 K） were achieved at last. Then high-energy ball milling was employed to prepare nano-sized particles. After that, the nano-sized Yb0.3Co4Sb12 particles were sintered by SPS apparatus to get bulk sample. Particle morphology and microstructure observation were performed by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). The thermoelectric properties of bulk materials were measured by ZEM-3 and LFA427. There were no decomposition and crystal form transition appeared after milling 10 h according to XRD patterns. The particle size decreased greatly according to FESEM and TEM observation and after sintering the grain size was ~500 nm and partly was less than 100 nm. Compared with the bulk without milling, the Seebeck coefficient after milling increased a little and thermal conductivity decreased 1/3. However, at the same time, the electrical conductivity decreased about 10 times so that the ZT of milled bulk Yb0.3Co4Sb12 decreased.