Ferromagnetic effects on non-Arrhenius diffusion of single interstitial helium solute in BCC Fe
Ferromagnetic effects on non-Arrhenius diffusion of single interstitial helium solute in BCC Fe
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BCC Fe 中单一间隙氦溶质非阿累尼乌斯扩散的铁磁效应
DOI：
10.1016/j.jnucmat.2019.07.014
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发表时间：
2019
影响因子：
3.1
通讯作者：
Zheng Yue
中科院分区：
文献类型：
--
作者：
Lai Kan;Wen Haohua;Liu Jianyi;Wu Yifeng;Zheng Yue
氦在金属中的扩散是气泡形核的关键原子过程之一。铁磁效应对体心立方铁的组织演变起着重要作用。采用自旋-晶格动力学方法研究了铁磁效应对单一间隙氦溶质在体心立方铁中非阿耳修斯扩散行为的影响。结果发现，铁磁效应显着降低氦的扩散率在低温下，但在高温下，统计上可以忽略不计的影响。此外，我们提出了一个粗粒度的公式来描述的非Arrhenius行为，和三个扩散模式被很好地定义取决于从主机原子的碰撞获得的热能和它的迁移势垒之间的竞争，例如，氦扩散揭示Arrhenius和爱因斯坦扩散模式，在低温和高温极限，分别。进一步讨论了体心立方铁中声子和磁振子的量子统计效应，发现这种效应导致了非线性的温度依赖性热能，从而导致了在Arrhenius扩散模区域的强非Arrhenius行为.氦在BCC Fe中的上述非阿氏扩散特征与氦在BCC W中扩散的情况一致[Wen et al.，J. Nucl. Mater. 493（2017）21; Woo等人，E96（2017）032133]，扩散参数与实验测量和其他计算结果一致。本文的工作有助于全面了解聚变堆结构材料中铁磁效应对辐照损伤积累的影响。
Helium diffusion in metals is one of the key atomic processes for bubble nucleation. Ferromagnetic effects play important roles on microstructural evolution in BCC iron. The spin-lattice dynamics simulations are performed to study the ferromagnetic effects on the non-Arrhenius diffusion behavior of single interstitial helium solute in BCC iron. It is found that the ferromagnetic effects significantly reduce the helium diffusivity at low temperatures, but give rise to a statistically negligible influence at high-temperatures. In addition, we propose a coarse-grained formula to describe the non-Arrhenius behavior, and three diffusion modes are well-defined depending on the competition between thermal energy of helium gained from the host atoms’ collisions and its migratory barrier, for instant, helium diffusion reveals Arrhenius- and Einstein-diffusion modes in the low- and high-temperature limits, respectively. Further, the effects of quantum statistics of both phonons and magnons in BCC Fe are also discussed, which is found to give rise to the non-linear temperature dependent thermal energy thus the strong non-Arrhenius behavior in the region of Arrhenius-diffusion mode. The above-mentioned non-Arrhenius diffusion feature of helium in BCC Fe is consistent with the cases of helium diffusion in BCC W [Wen et al., J. Nucl. Mater. 493 (2017) 21; Woo et al., Phys. Rev. E 96 (2017) 032133], and the diffusion parameters are in agreement with the experimental measurement and other calculations results. The current work could help to get a complete understanding of ferromagnetic effects on irradiation damage accumulation in structural materials of fusion reactors.