Point defect behavior in the B2 type intermetallic compounds CoAl
Point defect behavior in the B2 type intermetallic compounds CoAl
复制标题
B2型金属间化合物CoAl中的点缺陷行为
DOI：
10.1016/1359-6462(96)00204-7
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发表时间：
1996
影响因子：
6
通讯作者：
T. Tanahashi
中科院分区：
文献类型：
--
作者：
M. Kogachi;T. Tanahashi
由VIII和IIIb组分原子组成的B2型金属间化合物，如NiAl和CoAl，表现出不同类型的点缺陷，合金成分偏离化学计量。因此，确定详细的缺陷结构是一个非常重要的课题，以更清楚地了解其相关性的各种性质，在这些化合物。针对这一问题，近年来通过对NiAl、CoAl和FeAl化合物的粉末X射线衍射（XRD）研究，提出了一些新的研究方法。对前两种化合物的研究结果表明，在富Al区，除了大量的Ni（Co）空位和反结构缺陷（ASD）外，还形成了大量的Al空位和Al-ASD，它们在三缺陷模型（TRD模型）中被忽略了。将NiAl中的缺陷行为与属于同一组的其他化合物中的缺陷行为进行比较是一个有趣的问题：例如，CoAl和FeAl。因此，本论文的目的是确定出现在B2型金属间化合物CoAl作为从XRD和密度测量的组成的函数的缺陷结构。
The B2 type intermetallic compounds consisting of VIII and IIIb component atoms, such as the NiAl and CoAl, exhibit different types of point defects with deviation of alloy composition from the stoichiometry. Thus the determination of detailed defect structure is a very important subject for more clarification of its correlation to various properties in these compounds. Some work focusing on this problem has been recently presented by means of the powder X-ray diffraction (XRD) for the compounds NiAl, CoAl, and FeAl. The results for the former two compounds revealed that other than substantial amounts of Ni(Co) vacancies and antistructure defects (ASD), appreciable amounts of the Al-vacancy and Al-ASD which are neglected in the triple defect model (TRD model) were formed in the Al-rich composition region. It is an interesting problem to compare the defect behavior in NiAl with that in other compounds belonging to the same group: e.g., CoAl and FeAl. The aim of the present paper is thus to determine the defect structure appearing in the B2 type intermetallic compounds CoAl as a function of composition from the XRD and density measurements.