The Determination the Phason in Cu-Ga-Zn Icosahedral Quasicrystal Phase using with the Huang Diffuse Scattering method

黄漫散射法测定Cu-Ga-Zn二十面体准晶相中的相子

• 批准号: 15540306
• 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: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15540306/
• 关键词: Quasicrystal; Icosahedral; phason; x-ray diffraction; electron diffraction; diffuse scattering; Zn; X線回析; 電子線回析

The main aim of this research is to study the quasicrystal phase stability of Cu-Ga-Zn-Mg icosahedral phase. It have already been reported that a CuGaZnMg is an P-type icosahedral phase. But the other icosahedral phases are F-type icosahedral. We have made the program of the Huang scattering for icosaheral symmetry crystal. The experimental results o are in the icosahedral phases as follows.1)The pseudo-gap around the Fermi surface in the Cu-Ga-Zn-Mg icosahedral phase is observed by the UPS study and that in the Ga-Zn approximant is not observed. 2)The depth and width of the gap is 0.6 and 0.2eV, respectively. 3)It is very difficult for the x-ray study to be done. It seems that one of the reason is multi scattering effect is not ignored.The calculated results of the Huang scattering intensity are in the icosahedral phases as follows.1)The Huang diffuse distribution around the reflection along the 2-fold axis is elliptic spread toward the transverse direction. 2)The Huang diffuse distri … More bution around the reflection along the 5-fold and 3-fold axis is not elliptic spread toward the transverse direction and like the complex shape. 3)The diffuse scattering intensity distribution of Al-Pd-Mn 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 notjust 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.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 diffuse scattering components.As the comparison between experimental and calculation, we can think followings. The major defects in Al-Pd-Mn and Al-Cu-Fe can be exchange-type, 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 the defect 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. Less

这项研究的主要目的是研究Cu-Ga-Zn-mg二十面体相的准晶相稳定性。据报道，cugaznmg是P型二十面体相。但是其他二十面体相是F型二十面体。我们制作了黄体对称晶体的黄色散射程序。实验结果O在二十面体相中如下所示。1）UPS研究观察到Cu-Ga-Zn-Mg二十二个相的费米表面周围的伪空隙，并且在GA-ZN近似值中未观察到GA-ZN近似值。 2）间隙的深度和宽度分别为0.6和0.2EV。 3）很难完成X射线研究。看来原因之一是多散射效应不忽略。黄体相中的黄体散射强度的计算结果如下。1）沿2倍轴围绕反射周围的黄体弥漫性分布朝向横向方向椭圆形。 2）Huang扩散的发散...沿着5倍和3倍轴的反射周围的更多按钮不是椭圆形向横向方向传播，就像复合形状一样。 3）Al-PD-MN的弥散散射强度分布沿纵向方向是对称的，但Al-Cu-Fe的散射强度分布是不对称的。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。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，并且似乎由所有三个弥漫性散射成分的总和组成。在实验和计算之间的比较时，我们可以认为以下是跟随的。 Al-PD-MN和Al-Cu-Fe中的主要缺陷可以是交换型，它们是由原子和/或原子簇的互换产生的。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。缺陷的类型与交换型相似，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”无法用黄散射的近似来解释，因此可能是由大小效应引起的。较少的

项目成果

Photoemission Study of a Cu-Ga-Mg-Sc Icosahedral Phase

Cu-Ga-Mg-Sc 二十面体相的光电子研究

• 发表时间: 2005
• 期刊: UVSOR ACTIVITY REPORT 32(In print)
• 作者: M.Mori;R.Hashimoto;S.Motomura;D.Yoshimura;S.Kashimoto;T.Ishimasa
• 通讯作者: T.Ishimasa

S.Kashida, Y.Watanabe, T.Hasegawa, H.Iida, M.Mori, S.Savrasov: "Electronic Structure of Ag2S Band Calculation and photoelectron Spectroscopy"Solid State Ionics. 158. 167-175 (2003)

S.Kashida、Y.Watanabe、T.Hasekawa、H.Iida、M.Mori、S.Savrasov：“Ag2S 能带计算和光电子能谱的电子结构”固态离子学。