Iron nitride, α″-Fe16N2, around <100> interstitial type dislocation loops in neutron-irradiated iron
Iron nitride, α″-Fe16N2, around <100> interstitial type dislocation loops in neutron-irradiated iron
复制标题
氮化铁，α″-Fe16N2，中子辐照铁中大约 <100> 间隙型位错环
DOI：
10.1080/14786435.2021.1891317
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发表时间：
2021
影响因子：
1.6
通讯作者：
Nagai Y.
中科院分区：
文献类型：
--
作者：
Yoshiie T.;Inoue K.;Yoshida K.;Toyama T.;Satoh Y.;Nagai Y.
用原子探针层析(APT)和选区电子衍射(SAED)对中子辐照铁(99.99%)高温下形成的纳米析出物进行了研究。在常规的透射电子显微镜中，我们在体心立方铁晶格的{100}习惯面上发现了面团状的析出物，它形成于间隙型位错环的膨胀侧，其Burgers矢量为<；100>；通过APT和SAED的化学成分和晶格结构分析，确定了析出物为氮化物α“-Fe16N_2。在弱束暗场电子显微镜研究中，用衍射矢量和偏离布拉格条件的参数符号仔细分析了α“-Fe16N2的图像对比度，认为这是α”-Fe16N2在一个{100}面上的选择性显现。这些结果与α“-Fe16N_2和基质铁之间的晶体取向一致，从而弥合了在使用钠冷实验快堆JOYO或14 MeV D-T中子源RTNS-II进行中子辐照时形成Fe16N_2-Fe16N_2的知识空白。
Atom probe tomography (APT) and selected area electron diffraction (SAED) by transmission electron microscopy (TEM) were applied to nano-scale precipitates formed in a neutron-irradiated iron (99.99% pure) at high temperatures. In the conventional TEM, we discovered donut-type precipitates on the {100} planes that formed at the dilatational side of interstitial type dislocation loops with the Burgers vector of <100> on the habit planes of {100} in the bcc iron lattice. The precipitates were identified as nitride, bct α″-Fe16N2, by chemical composition and lattice structural analyses using APT and SAED. Image contrasts of the α″-Fe16N2in a weak beam dark-field electron microscopy study were carefully analysed with the diffraction vector and the sign of deviation parameter from the Bragg condition, and it was concluded to be a selective visualisation of α″-Fe16N2on one of the {100} planes. These results were in agreement with the crystallographic orientation between the α″-Fe16N2and matrix iron, thereby bridging a knowledge gap in α″-Fe16N2formation during neutron irradiation using a sodium-cooled experimental fast reactor, JOYO, or a 14 MeV D-T neutron source, RTNS-II.