A study of one-dimensional incommensurate modulated structure determination in high-resolution transmission electron microscopy

2014 ◽  
Vol 70 (6) ◽  
pp. 563-571 ◽  
Author(s):  
Xueming Li ◽  
Binghui Ge ◽  
Fanghua Li ◽  
Huiqian Luo ◽  
Haihu Wen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Dimensional Structure ◽  
Electron Diffraction Data ◽  
Image Deconvolution ◽  
Transmission Electron ◽  
Modulated Structures ◽  
Phase Extension

The methods for determining incommensurate modulated structures (IMSs) in high-resolution transmission electron microscopy have been studied and improved to a level more perfect than before. This is demonstrated by means of the IMS determination for Bi2.31Sr1.69CuO6+δas an example. First, as previously, the projected potential map (PPM) of the IMS with resolution 0.2 nm was obtained after image deconvolution from a [100] image. Secondly, the resolution of the PPM was enhanced to 0.1 nm through phase extension combined with the electron-diffraction data so that the substitutional and displacive modulation functions could be determined. Thirdly, a (2+1)-dimensional structure model that corresponds to the [100] projected IMS was built for calculating the related partial structure factors that were utilized to correct the experimental electron-diffraction intensities for both main and satellite reflections. After three cycles of diffraction-intensity correction and phase extension, all unoverlapped atoms projected along the [100] direction in Bi2.31Sr1.69CuO6+δwere resolved, and the modulations of substitution and displacement could be observed clearly. The substitution of Bi for Sr atoms at the Sr(O) columns was seen in the final PPM and verified by high-dimensional image simulation.

HRTEM Investigation of Precipitates in Al-Zn-In-Mg-Ti-Ce Anode Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 1036-1039
Author(s):  
Jing Ling Ma ◽  
Jiu Ba Wen ◽  
Yan Fu Yan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Hexagonal Structure ◽  
Orientation Relation ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Scanning Electron

The precipitates of Al-5Zn-0.02In-1Mg-0.05Ti-0.5Ce (wt %) anode alloy were studied by scanning electron microscopy, X-ray microanalysis, high resolution transmission electron microscopy and selected area electron diffraction analyses in the present work. The results show that the alloy mainly contains hexagonal structure MgZn2 and tetragonal structure Al2CeZn2 precipitates. From high resolution transmission electron microscopy and selected area electron diffraction, aluminium, Al2CeZn2 and MgZn2 phases have [0 1 -1]Al|| [1 -10]Al2CeZn2|| [-1 1 0 1]MgZn2orientation relation, and Al2CeZn2 and MgZn2 phases have the [0 2 -1]Al2CeZn2|| [0 1 -10]MgZn2orientation relation.

The Dodecagonal Quasicrystalline Telluride (Ta, V)1.6Te And Its Crystalline Approximant (TaV)97Te60

1998 ◽  
Vol 553 ◽  
Author(s):  
C. Reich ◽  
M. Conrad ◽  
F. Krumeich ◽  
B. Harbrecht
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Edge Length ◽  
X Ray ◽  
Transmission Electron ◽  
The Impact

AbstractThe dodecagonal (dd) quasicrystalline tantalum telluride dd Ta1.6Te and the crystalline approximant Ta97Te60 have been modified by partly replacing tantalum by vanadium. The impact of the substitution on the structures has been studied by X-ray and electron diffraction and by high-resolution transmission electron microscopy. The layered-type approximant structure of Ta83V14Te60 was determined by single crystal X-ray means. The partitioning of vanadium on 21 out of 29 crystallographically inequivalent metal sites is referred to, but not controlled by the Dirichlet domain volume available at the sites. A HRTEM projection of dd (Ta, V)1.6Te onto the dodecagonal plane is analysed with respect to the arrangement of (Ta, V)151Te74 clusters on the vertices of an irregular aperiodic square-triangle tiling, the edge length of which corresponds to the distance between the centres of two such clusters. The clusters comprise about 1 nm thick corrugated lamellae which are periodically stacked by weak Te-Te interactions.

Design of 2D-nanocrystals in water: preparation, structure and functionalization

2018 ◽  
Vol 90 (5) ◽  
pp. 833-844
Author(s):  
Leonid Aslanov ◽  
Valery Zakharov ◽  
Ksenia Paseshnichenko ◽  
Aleksandr Yatsenko ◽  
Andrey Orekhov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Composition ◽  
High Resolution ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Room Temperature ◽  
Energy Dispersive ◽  
X Ray ◽  
Transmission Electron

AbstractA new method for synthesis of 2D nanocrystals in water was proposed. The use of perfluorothiophenolate ions as surfactant allowed us to produce 2D single-crystal nanosheets of CaS at pH=9 and flat nanocrystals of PbS at pH=9 at room temperature. Mesocrystalline nanobelts of CdS and mesocrystals of PbS were obtained at pH=3–5 and pH=10–12, respectively. Morphology, structure and chemical composition of nanoparticles were characterized by high-resolution transmission electron microscopy, electron diffraction and energy dispersive X-ray spectroscopy. A mechanism of nanoparticles formation was discussed.

Transmission Electron Microscopy Studies of 5-cycled Na Alanate with Ti Based Additive

2005 ◽  
Vol 884 ◽  
Author(s):  
Carmen M. Andrei ◽  
John C. Walmsley ◽  
Randi Holmestad ◽  
Gianluigi A. Botton ◽  
Sesha S. Srinivasan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Hydrogen Storage Material ◽  
Hydrogen Diffusivity ◽  
Storage Material ◽  
X Ray ◽  
Transmission Electron ◽  
Edge Dislocations

AbstractTi doped NaAlH4 hydride is proposed as a reversible hydrogen storage material. In this work, the microstructure of NaAlH4 with 2% TiCl3 additive was studied after 5 hydrogen cycles using a combination of transmission electron microscopy (TEM) techniques including energy dispersive spectroscopy (EDS) X-ray analysis. Selected area diffraction and high-resolution (HR) imaging confirmed the presence of the NaH phase in the material. Electron diffraction was dominated by Al. HRTEM showed the presence of edge dislocations, which might influence the hydrogen diffusivity process in these materials.

Modulated structures of (Bi1−xPbx)2Sr2CoOy examined by high-resolution transmission electron microscopy

1992 ◽  
Vol 196 (1-2) ◽  
pp. 34-42 ◽  
Author(s):  
Kasumi Yanagisawa ◽  
Yoshio Matsui ◽  
Kaoru Shoda ◽  
Eiji Takayama-Muromachi ◽  
Shigeo Horiuchi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Transmission Electron ◽  
Modulated Structures

Vapor Deposited Ag2S Films as High Resolution Photoregistering Materials in The Infrared Region

1993 ◽  
Vol 334 ◽  
Author(s):  
J. Eneva ◽  
S. Kitova ◽  
A Panov ◽  
H. Haefke
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Composition ◽  
High Resolution ◽  
Electron Diffraction ◽  
Narrow Band ◽  
Stoichiometric Composition ◽  
Infrared Region ◽  
Processing Conditions ◽  
Transmission Electron

AbstractAg2S as a narrow band gap semiconductor is appropriate for photoimaging in the infrared (IR) region. Co-evaporation of Ag and S from two separate sources was used for preparing of thin Ag2S films with different Ag/S ratio. Gelatine subbed glass plates were used as substrates. The structure of the films obtained was examined by transmission electron microscopy and electron diffraction. The effects of chemical composition, film thickness and processing conditions on the photographic parameters were studied.It is shown that after appropriate processing thin Ag2S films with stoichiometric composition can. be successfully used as high resolution (1600 lines/mm) photographic materials in the IR region.

Three-Dimensional Structure of Helical and Zigzagged Nanowires Using Electron Tomography

2008 ◽  
Vol 1144 ◽  
Author(s):  
Han Sung Kim ◽  
Yoon Myung ◽  
Chang Hyun Kim ◽  
Seung Yong Bae ◽  
Jae-Pyoung Ahn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Helical Structure ◽  
Axial Direction ◽  
Dimensional Structure ◽  
Gan Nanowires ◽  
Transmission Electron

ABSTRACTElectron tomography and high-resolution transmission electron microscopy were used to characterize the unique three-dimensional structures of helical or zigzagged GaN, ZnGa2O4 and Zn2SnO4 nanowires. The helical GaN nanowires adopt a helical structure that consists of six equivalent <0-111> growth directions with the axial [0001] direction. The ZnGa2O4 nanosprings have four equivalent <011> growth directions with the [001] axial direction. The zigzagged Zn2SnO4 nanowires consisted of linked rhombohedrons structure having the side edges matched to the <011> direction, and the [111] axial direction.

scholarly journals Odd electron diffraction patterns in silicon nanowires and silicon thin films explained by microtwins and nanotwins

2009 ◽  
Vol 42 (2) ◽  
pp. 242-252 ◽  
Author(s):  
Cyril Cayron ◽  
Martien Den Hertog ◽  
Laurence Latu-Romain ◽  
Céline Mouchet ◽  
Christopher Secouard ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Silicon Nanowires ◽  
Si Nanowires ◽  
Silicon Thin Films ◽  
Transmission Electron ◽  
Diffraction Patterns

Odd electron diffraction patterns (EDPs) have been obtained by transmission electron microscopy (TEM) on silicon nanowires grownviathe vapour–liquid–solid method and on silicon thin films deposited by electron beam evaporation. Many explanations have been given in the past, without consensus among the scientific community: size artifacts, twinning artifacts or, more widely accepted, the existence of new hexagonal Si phases. In order to resolve this issue, the microstructures of Si nanowires and Si thin films have been characterized by TEM, high-resolution transmission electron microscopy (HRTEM) and high-resolution scanning transmission electron microscopy. Despite the differences in the geometries and elaboration processes, the EDPs of the materials show great similarities. The different hypotheses reported in the literature have been investigated. It was found that the positions of the diffraction spots in the EDPs could be reproduced by simulating a hexagonal structure withc/a= 12(2/3)1/2, but the intensities in many EDPs remained unexplained. Finally, it was established that all the experimental data,i.e.EDPs and HRTEM images, agree with a classical cubic silicon structure containing two microstructural defects: (i) overlapping Σ3 microtwins which induce extra spots by double diffraction, and (ii) nanotwins which induce extra spots as a result of streaking effects. It is concluded that there is no hexagonal phase in the Si nanowires and the Si thin films presented in this work.

Synthesis of Bamboo-Shaped Gallium Nitride Nanorods

2005 ◽  
Vol 475-479 ◽  
pp. 3575-3578
Author(s):  
Zhi Zhong Dong ◽  
Haiyong Gao ◽  
Cheng Shan Xue ◽  
Zhi Hua Dong ◽  
Jian Ting He
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
High Resolution ◽  
Electron Diffraction ◽  
Average Length ◽  
Rf Magnetron Sputtering ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Infrared Spectrophotometer

Heagonal GaN nanorods have been synthesized through ammoniating ZnO/Ga2O3 films deposited by radio frequency(rf) magnetron sputtering on Si(111) substrates.X-ray diffraction(XRD), Fourier transform infrared spectrophotometer (FTIR), transimission electron microscopy(TEM), high-resolution transmission electron microscopy(HRTEM) and selected-area electron diffraction (SAED) are used to analyze the structure,composition and morphology of the synthesized GaN nanorods. TEM result shows that GaN nanorods own bamboo-shaped morphalogy and have a single-crystal hexagonal wurtzite structure.The average length and dimeter of the nanorods are 3μm and 50 nm espectively.Ga2O3 and NH3 reactived directly and synthesized GaN nanorods without any catalyzer and the process of space-confined reactions.

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