%0 Journal Article
%T Interaction between impurity nitrogen and tungsten: a first-principles investigation<br>
%A Liu Yue-Lin
%A Jin Shuo
%A Zhang Ying
%A <br>
%J 中国物理 B
%D 2012
%I 
%X We investigate the stability, diffusion, and impurity concentration of nitrogen in intrinsic tungsten single crystal employing a first-principles method, and find that a single nitrogen atom is energetically favourable for sitting at the octahedral interstitial site. A nitrogen atom prefers to diffuse between the two nearest neighboring octahedral interstitial sites with a diffusion barrier of 0.72 eV. The diffusion coefficient is determined as a function of temperature and expressed as D(N)=1.66×10-7exp (-0.72/kT). The solubility of nitrogen is estimated in intrinsic tungsten in terms of Sieverts' law. The concentration of the nitrogen impurity is found to be 4.82×10-16  -3 at a temperature of 600 K and a pressure of 1 Pa. A single nitrogen atom can easily sit in an off-vacancy-centre position close to the octahedral interstitial site. There exists a strong attraction between nitrogen and a vacancy with a large binding energy of 1.40 eV. We believe that these results can provide a good reference for the understanding of the behaviour of nitrogen in intrinsic tungsten.
%K tungsten
%K nitrogen
%K diffusion
%K first-principles<br>
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=CD8D6A6897B9334F09D8D1648C376FB4&aid=AF837C3964F7310F0E56D79D4C18ECEB&yid=99E9153A83D4CB11&vid=659D3B06EBF534A7&iid=CA4FD0336C81A37A&sid=7C7395D2DC9F1651&journal_id=1009-1963&journal_name=中国物理&referenced_num=0&reference_num=31