Electron Diffraction for the Thermomagnetic Analysis of a Ferromagnetic

A thermomagnetic analysis of ferromagnetic invar was made by the diffraction procedure utilizing the electorns accelerated over 200 keV. An electron beam served for heating the specimen by electron bombardment. An empirical formula has been proposed for analying the observations.     

Electron Diffraction of Microcrystals on the Example of Lysozyme

Crystallography Reports - Electron diffraction of microcrystals is a new powerful tool of cryo-electron microscopy, which makes it possible to determine the structure of three-dimensional crystals...     

电子背散衍射花样的数学特征

电子背散衍射(EBSD)花样揭示了材料的物相成分、晶体结构、晶粒取向、晶粒大小和晶界的信息。EBSD花样非常复杂,通常需要借助专门的计算软件才能解析。本文系统地研究了EBSD花样的数学特征,建立了任意晶体取向与EBSD花样之间的数理关系,推导了面心立方、体心立方和六方晶体的基本晶带轴的理论EBSD花样的数学特征,以及面心立方晶体的(001)<110>取向和(001)<100>取向的理论菊池(Kikuchi)花样特征。在实测EBSD花样的分析中与各晶系各点阵的基本晶带轴的理论EBSD花样特征比较,即通过图像特征对比,就可以直接确定实测EBSD花样所属的晶系、点阵和Kikuchi线交点对应的晶带轴[uvw],再由基本晶带轴的坐标计算出晶体取向,还能提供基本晶面信息,如原子密排晶面在样品中的空间分布,这有利于晶体的变形或生长机理研究。EBSD为单晶芯片质量检验提供了新方法。     

X-ray Diffraction Analysis and Electron Microscopy of the Carbon Fiber Structure

Crystallography Reports - A technique for studying the carbon-fiber structure using X-ray diffraction and electron microscopy has been developed. Average crystal-structure parameters are determined...     

New Approaches to Precise Measurements of Electron Diffraction Patterns

Crystallography Reports - To increase the measurement precision of electron diffraction patterns, a deep upgrade of EMR-102 diffractometer is performed, its operation parameters are studied, and a...     

Electron Microscopy and Electron Diffraction Studies of Morphology and Crystal Structure of Natural Silicas

Crystallography Reports - The development of fundamental and applied geology requires an ever-increasing amount of data on the structures and properties of rocks at different scales. Of particular...     

Computer Simulation of Electron Diffraction Studies of Various Microcrystalline Bodies

Electron diffraction of various microcrystalline bodies has been studied and examined by using computer simulation. Diffracted intensity studies indicated that the peak height increases with the scattering factor. First peak of FCC packed and crystalline observed at S = 6.01 Å and for HCP S = 5.0 Å. The amplitude of waves is most probably the same in the distribution function and providing a spectrum of interatomic distances in the crystalline bodies.     

Transmission Electron Microscope Study of Secondary Phases in Cr3+:LiCaAlF6 Single Crystals

Cr³⁺-doped LiCaAlF₆ single crystals, considered as promising laser materials, contain secondary phases of different sizes and shapes which can be observed as "needles" or "dust" by light microscopy. TEM investigations presented in this paper give evidence for precipitation as the reason for the so-called microscopic "dust". The elongated shape of the so-called "needles" seems to be a consequence of the microscopic growth of facets which become visible by the decoration of the facet boundaries with microscopic precipitates.     

Investigation of the Polytypism in Layered CdInGaS4 Crystals by Electron Diffraction Methods

Crystallography Reports - The polytypism in layered CdInGaS4 crystals grown by chemical transport reaction has been investigated by previously developed methods of oblique-texture electron...     

Study of the Processes Induced by Femtosecond Laser Radiation in Thin Films and Molecular-Cluster Beams Using Ultrafast Electron Diffraction

Crystallography Reports - The coherent lattice dynamics in thin crystalline Sb and Bi films has been investigated using ultrafast electron diffraction. The samples were exposed to Ti:sapphire...     

GaAs-GaN键合界面热应力的电子背散射衍射研究

采用扫描电镜(SEM)和电子背散射衍射(EBSD)技术,观察和分析了GaAs和GaN晶片热压键合的界面热应力和晶片键合质量.利用EBSD测量了GaAs-GaN键合界面的菊池花样质量、晶格转动、晶格错配和位错密度等应力敏感参数.结果表明,晶片键合质量良好,键合界面中心区域的热应力小于边缘区域的热应力.GaN层和GaAs层中的应力影响范围,在中心区域分别约为100 nm和300 nm,在边缘区域分别约为100 nm和500nm.EBSD显示的应力分布图与模拟应力场相似.模拟和计算表明,最大剥离应力和剪切应力分布在键合界面的边缘.剥离应力是导致晶片解键合的主要原因.     

Method of Contrast Enhancement and Background Correction in Electron Diffraction Patterns of Polycrystalline Materials

Crystallography Reports - Noise minimization and suppression is one of the most important problems in image processing. Background correction and detection of weak reflections were performed using...     

正交晶系单晶标准透射电子衍射斑点图及绘制原理

分析透射电子衍射斑点图对于研究晶体结构十分重要,常通过对比法来分析衍射斑点图.本文介绍了单晶标准透射电子衍射斑点图的绘制原理,并绘制了正交晶系的标准衍射斑点图.完善了单晶标准衍射斑点图数据,为科研工作者提供了便利.     

Proton Spin-Lattice Relaxation Dispersion Study of the Ferroelectric Smectic Phases in Dobambc

The frequency dispersion of the proton spin-lattice relaxation rates T^?1 ₁ in the ferroelectric smectic phases of DOBAMBC has been determined in the MHz region and analyzed in terms of the order fluctuations, self-diffusion, and rotational contributions to T^?1 ₁. In the smectic C* phase the main rate determining contribution are order fluctuations with a T^?1 ₁ ∝ ν^?1/2 _L frequency dependence, whereas in the smectic H* phase the translational diffusion, which is slower than in the smectic H* phase, determines the dispersion of T^?1 ₁.     

Electron Microscopy in the Study of Lunar Regolith

Crystallography Reports - The results of long-term mineralogical studies of the lunar regolith, obtained using analytical scanning and transmission electron microscopy, are presented. These studies...     

不同材料构成声子晶体带隙特性研究

基于平面波展开法研究不同材料构成声子晶体带隙特性.数值模拟得到碳散射体与不同基体材料构成正方形声子晶体XY模式的能带结构,环氧树脂基体与不同散射体材料构成正方形声子晶体XY模式的能带结构,正方形和三角形结构声子晶体Z模式的能带结构.结果表明增加散射体与基体的密度比,更容易出现带隙,三角形结构相比正方形结构更易形成较宽带隙.研究结论为声子晶体器件制作提供理论依据.     

Crystallization and Preliminary X-Ray Diffraction Study of the C-Terminal Fragment of Myomesin-2

Crystallography Reports - The recombinant С-terminal fragment of myomesin-2 was purified to a homogeneous state. The crystallization conditions for the С-terminal fragment of myomesin-2...     

Single Crystal X-ray Diffraction Study of a Pure Natrolite Sample

The crystal structure of a pure natrolite sample, Na₂(Al₂Si₃O₁₀)·2H₂O, coming from Asheken, Ethiopia, has been analysed by single crystal X-ray diffraction. It crystallizes within the orthorhombic space group Fdd2, with the following cell constants: a = 18.2930(2) Å; b = 18.6430(5) Å; c = 6.5860(5) Å; V = 2246.07(18) Å³. The three-dimensional framework of this hydrated aluminosilicate zeolite is made up by chains of corner-sharing SiO₄ and AlO₄ tetrahedra down c; the chains are held together by sharing the external vertices of tetrahedra; water molecules and Na⁺ extra-framework cations fill up the resulting cavities, the latter forming irregular NaO₆ octahedra. Hydrogen bonds complete the array.