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篇目详细内容 |
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【篇名】 |
Effect of the La addition content on valence electron structure and properties of ZrB2 ceramics |
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【刊名】 |
Frontiers of Materials Science in China |
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【刊名缩写】 |
Front. Mater. Sci. China |
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【ISSN】 |
1673-7377 |
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【EISSN】 |
1673-7482 |
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【DOI】 |
10.1007/s11706-010-0083-3 |
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【出版社】 |
Higher Education Press and Springer-Verlag Berlin
Heidelberg |
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【出版年】 |
2010 |
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【卷期】 |
4
卷3期 |
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【页码】 |
262-265
页,共
4
页 |
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【作者】 |
Jin-Ping LI;
Yan WANG;
Qing LIU;
Xiao-Guang LUO;
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【关键词】 |
ZrB2; La substitution; valence electron structure (VES); properties |
【摘要】 |
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ZrB2 is a combined bonding compound composed of strong covalent bonds which make it difficult to sinter and densify. Thus, rare earth or other metal elements are usually used to be sintering additives to improve its sintering properties. To forecast properties of ZrB2 solid solutions with addition of lanthanum, their valence electron structure (VES) was calculated by using the empirical electron theory (EET) of solids and molecules, and the effect of lanthanum with various proportion on the VES and properties of ZrB2 ceramics has been studied. The results show that with the increase of the lanthanum addition content, the hybridization steps of Zr and B atoms of ZrB2 solid solutions are still A16 and 5, respectively. The hybridization step of lanthanum is always A1. The covalent electron numbers and bonding energy of the strongest bonds of the ZrB2 matrix decrease with the lanthanum addition content increase. These suggest that the addition of lanthanum will improve the fracture toughness and decrease the hardness, crystal cohesive energy and melting point of ZrB2. In a word, its sintering properties are improved, and its densities are increased. |
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