| CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES |
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Preparation and Characterization of Grain Size Controlled LaB6 Polycrystalline Cathode Material |
| BAO Li-Hong, ZHANG Jiu-Xing, ZHOU Shen-Lin, WEI Yong-Feng |
| Key Laboratory of Advanced Functional Materials (Ministry of Education), College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 |
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| Cite this article: |
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BAO Li-Hong, ZHANG Jiu-Xing, ZHOU Shen-Lin et al 2010 Chin. Phys. Lett. 27 107901 |
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Abstract The grain size controlled bulk Lanthanum hexaboride (LaB6) cathode material was prepared by using the spark plasma sintering method in an oxygen free system. The starting precursor nanopowders with average grain size of 50 nm were prepared by high−energy ball milling. The nanopowder was fully densified at 1300°C, which is about 350°C lower than the sintering temperature of the coarse powders. The thermionic emission current density was measured to be 42.0 A/cm2, which is much higher than 24.2 A/cm2 of coarse powders and Vickers hardness to be 1860 kg/mm2, which is also higher than 1700 kg/mm2 of coarse one. These results indicate that refining the powder grain size to nano level was beneficial for reducing the sintering temperature and promoting the thermionic emission and mechanic properties.
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| Keywords:
79.40.+z
52.50.-b
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Received: 22 June 2010
Published: 26 September 2010
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