First-principles study of the thermodynamics of hydrogen-vacancy interaction in fcc iron
First-principles study of the thermodynamics of hydrogen-vacancy interaction in fcc iron
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DOI：
10.1103/physrevb.82.224104
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发表时间：
2010-12
影响因子：
3.7
通讯作者：
R. Nazarov;T. Hickel;J. Neugebauer
中科院分区：
文献类型：
--
作者：
R. Nazarov;T. Hickel;J. Neugebauer
结合热力学概念与从头算计算，并考虑各种磁结构，研究了面心立方铁体晶体中空位和氢的相互作用。我们表明，单空位可捕获多达6个氢原子。所有研究的点缺陷（单空位、间隙位置的氢以及氢 - 空位复合物）在反铁磁面心立方铁中都会产生各向异性弹性场，并显著改变系统的局部和总磁化强度。所提出的热力学模型能够确定在给定温度和储氢器中氢化学势的情况下的平衡空位浓度和溶解氢浓度。在富氢条件下，发现晶体中的空位浓度急剧增加。
The interaction of vacancies and hydrogen in an fcc iron bulk crystal was studied combining thermodynamic concepts with ab initio calculations and considering various magnetic structures. We show that up to six H atoms can be trapped by a monovacancy. All of the studied point defects (single vacancy, H in interstitial positions, and H-vacancy complexes) cause an anisotropic elastic field in antiferromagnetic fcc iron and significantly change the local and total magnetization of the system. The proposed thermodynamical model allows the determination of the equilibrium vacancy concentration and the concentration of dissolved hydrogen for a given temperature and H chemical potential in the reservoir. For H-rich conditions a dramatic increase in the vacancy concentration in the crystal is found.