The Phason Observation in Al-Pd-Mn Icosahedral Quasicrystals using with the temperature dependence of the lattice constants

利用晶格常数的温度依赖性观察 Al-Pd-Mn 二十面体准晶中的相子

基本信息

批准号：
11640346
负责人：
MORI Masahiro
金额：
$ 2.3万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640346/
关键词：
Quasicrystal Icosahedral phasion thermal expansion aluminum electron diffraction x-ray diffraction diffuse scattering 相変態変調構造 X 線回折熱膨張

项目摘要

The main aim of this research is to study the quasicrysta phase stability of Al-Pd-Mn icosahedral phase. It have already been reported that an A1PdMn and the other icosahedral phases is not only an F-type icosahedral phase, but can be F2-type and F2M-type icosahedral phases. The experimental results of the diffuse scattering intensity are as follows.1) The diffuse distribution of Al-Pd-Mu is elliptic spread toward the transverse direction, but that of Al-Cu-Fe is asymmetrical rhombic shape. 2) The diffuse scattering intensity distribution of Al-Pd-Mu is symmetrical along the longitudinal direction, but that of Al-Cu-Fe is asymmetric. The reason, called "asymmetrical" in this case, is that the center of the rhombus is not just on the diffraction point, but is located on the slightly inside. 3) The shape of diffuse intensity contour depends on the intensity. 4) The intensity of the diffuse scattering in Al-Cu-Fe depends little on the temperature below 300K.5) The diffuse intensity is pro … More portional to the nth power of the magnitude of q. The values of n range between -2 and -3.5 and depend on the direction and reflection.Therefore, it is thought that the diffuse scattering is mainly produced by the defects. In the defects, a defect, called a (frozen) "phason" proper to a quasicrystal, is naturally included besides an impurity and/or defect included in a "usual" crystal. The experimental result seems to show the limit of elastic approximation as Huang scattering. The contour of the diffuse scattering intensity cannot individually be explained as every map of Huang scattering, and seems to consist of the sum of all three components.As the comparison between experimental and calculation, we can think followings. The major defects in Al-Pd-Mu and Al-Cu-Fe can be exchange-type defects which are created by interchange of atoms and/or atomic clusters. However, the concentration of atoms and atomic clusters is unchanged from the ideal structure by this type of defect. Random phason is clearly classified into this type.The type of a defect in the Al-Cu-Fe phase is similar to the exchange-type but is accompanied by deviation of concentration of atoms and atomic clusters from the ideal state. As the "asymmetrical" cannot be explained with the approximation of Huang scattering, it is probably caused by a size effect.The major defects are exchange-type defects which are created by interchange of atoms and/or atomic clusters. And the concentration of atoms and atomic clusters is unchanged from the ideal structure by this type of defect. Random phason is clearly classified into this type. The results indicate presence of additional type of defect in the Al-Cu-Fe phase. The "asymmetrical" and the nth power dependence cannot be explained with the elastic approximation of Huang scattering. Less

这项研究的主要目的是研究Al-PD-MN冰糖相的准晶相稳定性。据报道，A1PDMN和其他冰状体相不仅是F型冰状体相，而且可以是F2型和F2M型ICOSEHEDRAL相。弥漫性散射强度的实验结果如下。1）Al-PD-MU的弥漫性分布向横向方向椭圆形扩散，但这2）Al-Pd-Mu的弥漫性散射强度分布沿纵向方向是对称的，但是Al-Cu-fe的弥散性散射是不对称的。在这种情况下，称为“不对称”的原因是菱形的中心不仅在衍射点上，而且位于稍微内部。 3）扩散强度轮廓的形状取决于强度。 4）Al-Cu-Fe中弥漫性散射的强度几乎不取决于低于300K的温度。5）弥漫强度是pro的……更多的一部分，即Q幅度的第n个功率。 n的值范围为-2和-3.5，并取决于方向和反射。因此，人们认为弥散散射主要由缺陷产生。在缺陷中，除了在“常规”晶体中包含的杂质和/或缺陷之外，自然还包括一个称为A（冷冻）“ Phason”的缺陷。实验结果似乎显示了弹性散射的弹性近似的极限。弥漫性散射强度的轮廓不能单独解释为所有黄色散射的图，并且似乎包括所有三个组件的总和。由于实验和计算之间的比较，我们可以认为以下。 Al-PD-MU和Al-Cu-Fe中的主要缺陷可以是通过原子和/或原子簇的交换产生的交换型缺陷。但是，由于这种类型的缺陷，原子和原子簇的浓度与理想结构没有变化。随机阶段显然被分类为这种类型。 Al-Cu-Fe相中的缺陷类型与交换型相似，但通过原子浓度和原子簇偏离理想状态来实现。由于“不对称”无法用黄散散射的近似来解释，因此可能是由大小效应引起的。主要缺陷是由原子和/或原子簇的交换所产生的交换型缺陷。由于这种类型的缺陷，原子和原子簇的浓度与理想结构没有变化。随机阶段显然被分类为这种类型。结果表明在Al-Cu-FE相中存在其他类型的缺陷。不能用黄色散射的弹性近似来解释“不对称”和n个功率依赖性。较少的