Application of scanning electron diffraction in the transmission electron microscope for the characterisation of dislocations in minerals

AbstractWe present an application of scanning electron diffraction for the characterisation of crystal defects in olivine, quartz and phase A (a high pressure hydrated phase). In this mode, which takes advantage of the ASTAR™ module from NanoMEGAS, a slightly convergent probe is scanned over the sample with a short acquisition time (a few tens of ms) and the spot patterns are acquired and stored for further post-processing. Originally, orientation maps were constructed from automatic indexing at each probe location. Here we present another application where images are reconstructed from the intensity of diffraction spots, producing either so-called ‘virtual’ bright- or dark-field images. We show that these images present all the characteristics of contrast (perfect crystal or defects) of conventional transmission electron microscopy images. Data are acquired with a very short time per probe location (a few tens of milliseconds), this technique appears very attractive for the characterisation of beam-sensitive materials. However, as the acquisition is done at a given orientation, fine tuning of the diffraction conditions at a given location for each reflection is not possible. This might present a difficulty for some precise, quantitative contrast analysis.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.1036 ◽

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.

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An Inexpensive Approach for Bright-Field and Dark-Field Imaging by Scanning Transmission Electron Microscopy in Scanning Electron Microscopy

Microscopy and Microanalysis ◽

10.1017/s1431927613014049 ◽

2014 ◽

Vol 20 (1) ◽

pp. 124-132 ◽

Cited By ~ 6

Author(s):

Binay Patel ◽

Masashi Watanabe

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Scanning Transmission Electron Microscopy ◽

Lattice Spacing ◽

Dark Field ◽

Bright Field ◽

Specimen Holder ◽

Transmission Electron ◽

Scanning Transmission ◽

Scanning Electron

AbstractScanning transmission electron microscopy in scanning electron microscopy (STEM-in-SEM) is a convenient technique for soft materials characterization. Various specimen-holder geometries and detector arrangements have been used for bright-field (BF) STEM-in-SEM imaging. In this study, to further the characterization potential of STEM-IN-SEM, a new specimen holder has been developed to facilitate direct detection of BF signals and indirect detection of dark-field (DF) signals without the need for substantial instrument modification. DF imaging is conducted with the use of a gold (Au)-coated copper (Cu) plate attached to the specimen holder which directs highly scattered transmitted electrons to an off-axis yttrium-aluminum-garnet (YAG) detector. A hole in the copper plate allows for BF imaging with a transmission electron (TE) detector. The inclusion of an Au-coated Cu plate enhanced DF signal intensity. Experiments validating the acquisition of true DF signals revealed that atomic number (Z) contrast may be achieved for materials with large lattice spacing. However, materials with small lattice spacing still exhibit diffraction contrast effects in this approach. The calculated theoretical fine probe size is 1.8 nm. At 30 kV, in this indirect approach, DF spatial resolution is limited to 3.2 nm as confirmed experimentally.

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Randomly oriented twin domains in electrodeposited silver dendrites

Journal of the Serbian Chemical Society ◽

10.2298/jsc140306045i ◽

2015 ◽

Vol 80 (1) ◽

pp. 107-113 ◽

Cited By ~ 4

Author(s):

Evica Ivanovic ◽

Nebojsa Nikolic ◽

Velimir Radmilovic

Keyword(s):

Electron Microscopy ◽

Orientation Imaging Microscopy ◽

Dark Field ◽

High Angle ◽

Orientation Imaging ◽

Transmission Electron ◽

Annular Dark Field ◽

Silver Dendrites ◽

Z Contrast ◽

Scanning Electron

Silver dendrites were prepared by electrochemical deposition. The structures of Ag dendrites, the type of twins and their distribution were investigated by scanning electron microscopy (SEM), Z-contrast high angle annular dark field transmission electron microscopy (HAADF), and crystallografically sensitive orientation imaging microscopy (OIM). The results revealed that silver dendrites are characterized by the presence of randomly distributed 180? rotational twin domains. The broad surface of dendrites was of the {111} type. Growth directions of the main dendrite stem and all branches were of <112> type.

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Electron microscopic investigation of the structure and morphology of syndiotactic polypropylene

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153762 ◽

1989 ◽

Vol 47 ◽

pp. 358-359

Author(s):

Andrew J. Lovinger ◽

Bernard Lotz ◽

Don D. Davis

Keyword(s):

Electron Microscopy ◽

Electron Diffraction ◽

Dark Field ◽

Microscopic Investigation ◽

Electron Microscopic Investigation ◽

Dilute Solution ◽

Electron Microscopic ◽

Syndiotactic Polypropylene ◽

Selected Area Electron Diffraction ◽

Transmission Electron

In contrast to its isotactic isomer, syndiotactic polypropylene has received only little attention. Our main source of understanding of its structure is the X-ray study by Conradini et al., who found the chains to have a (t2g2)2 conformation (corresponding to a 4∗2/1 helix with molecular repeat 0.74 nm), and to be packed in a C-centered unit cell as shown in the left side of Fig. 1. We have recently begun a study of the structure, crystallization, and morphology of syndiotactic polypropylene using electron microscopy and diffraction. Here we concentrate specifically on the electron-diffraction evidence as a function of temperature, in order to obtain an understanding of the evolution and variation of structure in this polymer.Thin films of syndiotactic polypropylene (synthesized by Dr. R. E. Cais as reported previously) were prepared by casting from dilute solution in xylenes at ca. 140°c onto freshly cleaved mica substrates. Following evaporation of the solvent, they were melted and then isothermally crystallized at a variety of temperatures. After shadowing with Pt/C and coating with carbon, they were floated off their substrates for examination by transmission electron microscopy (bright- and dark-field) and selected-area electron diffraction at 100-200 keV.

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The Art and Application of Large Angle Convergent Beam Electron Diffraction

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.186.16 ◽

2012 ◽

Vol 186 ◽

pp. 16-19 ◽

Cited By ~ 1

Author(s):

Elżbieta Jezierska

Keyword(s):

Electron Diffraction ◽

Large Angle ◽

Antiphase Boundary ◽

Antiphase Domain ◽

Dark Field ◽

Convergent Beam Electron Diffraction ◽

Intermetallic Alloys ◽

Beam Electron ◽

Transmission Electron ◽

Convergent Beam

The antiphase domain structure in Ni3Al and Al3Ti+Cu intermetallic alloys was recognized by conventional transmission electron microscopy and large angle convergent beam electron diffraction methods. In the case of antiphase boundary the superlattice excess line is split into two lines with equal intensity on bright and dark field LACBED pattern. This splitting can be considered as typical and used to identify APBs. The recognition between perfect structure of the defect-free matrix and the screw deviation around the nanopipes in GaN epilayers was performed with high accuracy using Zone Axis LACBED images.

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Translation symmetries in convergent-beam electron diffraction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100112592 ◽

1984 ◽

Vol 42 ◽

pp. 524-525

Author(s):

B. F. Buxton ◽

M. D. Shannon ◽

J. A. Eades

Keyword(s):

Electron Diffraction ◽

Perfect Crystal ◽

Convergent Beam Electron Diffraction ◽

Transmission Electron ◽

Infinite Crystal ◽

Full Symmetry ◽

The Subject ◽

Diffraction Patterns ◽

Convergent Beam ◽

The Ideal

For crystallographic studies in the transmission electron microscope the “ideal” sample is considered to be a parallel sided slab, oriented perpendicular to the electron beam, cut from perfect crystal. Such a slab does not, in general, have the full symmetry of the crystal from which it has been cut. As a result, there arises the question as to whether the symmetry observed in the diffraction pattern reflects the symmetry of the slab or that of the infinite, perfect crystal. For the most part this matter is clear but there is one class of situation that has been (and perhaps still is) the subject of some debate.If the infinite crystal contains glide planes or screw axes for which the corresponding translation is not parallel to the slab, then, strictly speaking, the slab does not have these symmetries. Normally, however, in transmission electron diffraction patterns, symmetry features that result from the presence of these symmetry elements are observed (although Goodman asserts that they should not be).

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TEM-nanometer-area electron diffraction of interfaces in semiconductor superlattices

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100174746 ◽

1990 ◽

Vol 48 (4) ◽

pp. 322-323

Author(s):

Nobuo Tanaka ◽

Kazuhiro Mihama ◽

Hiroshi Kakibayashi ◽

Kazuhiro Ito

Keyword(s):

Electron Diffraction ◽

Structural Information ◽

Diffraction Method ◽

Dark Field ◽

Compositional Variation ◽

Imaging Method ◽

Good Correspondence ◽

Transmission Electron ◽

Electron Microscopes ◽

First Time

Recent progress of transmission electron microscope(TEM) enables us to perform electron diffraction from nm-sized areas(nano-diffraction) with a good correspondence with HREM. Nano-diffraction is useful for obtaining local structural information. One of the present authors (NT) applied the method to interfaces of GaAs/AlGaAs superlattices for detection of compositional variation of aluminum(Al) and to nm-sized γ-iron crystallites in MgO for analysis of the strain. Although nano-diffraction has been performed successfully in STEM instruments by Cowley and others, the method in TEM has an advantage in a good compatibility with the structure-imaging method and the established bright and dark-field(BF & DF) imaging methods. In the present paper we report for the first time the detection of lattice strain around interfaces of InP/InGaP strained superlattices as well as results of GaAs/InGaAs, GaAs/AlGaAs and Ge/Si superlattices by using the TEM nano-diffraction method.The nano-diffraction was performed with 200 kV transmission electron microscopes of Cs = 1.2 mm(JEM-2000FX) and Cs = 0.5mm(JEM-2010L Before focusing an election probe, HREM and DF images of the interfaces were taken in the [100] zone axis at 100-400 k in direct magnification.

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Investigation of Subcontact Layers in SiC after Diffusion Welding

Materials Science Forum ◽

10.4028/www.scientific.net/msf.600-603.647 ◽

2008 ◽

Vol 600-603 ◽

pp. 647-650 ◽

Cited By ~ 2

Author(s):

Oleg Korolkov ◽

Natalja Sleptsuk ◽

Alla A. Sitnikova ◽

Mart Viljus ◽

Toomas Rang

Keyword(s):

Silicon Carbide ◽

Electron Diffraction ◽

Diffraction Pattern ◽

Amorphous Layer ◽

Interface Layer ◽

Dark Field ◽

Diffusion Welding ◽

Transmission Electron ◽

First Results ◽

Diffraction Picture

In our early analytic reports [1,2] has been made the supposition that during the diffusion welding (DW) in subcontact area of SiC is formed the intermediate amorphous layer. In the present work are given the first results of transmission electron microscopy (TEM) and electron diffraction investigations of subcontact layers in n0-n- 4H-SiC. TEM examinations show that the boundary between aluminium and silicon carbide looks like stripy interface layer of ~ 25 nm thickness. This is the evidence that during diffusion welding in subcontact surface layer of SiC the shear micro deformations have been taking place and due to this process the plane inclusions of small-grained phase have been appeared. The image of contact area obtained in diffracted SiC rays (dark field) apparently confirms that stripy zone belongs to silicon carbide because the aluminium (black zone) fell out of contrast. Diffraction picture obtained from bulk zone of silicon carbide looks like monocrystallin, but the micro diffraction pattern obtained from the subcontact (stripy zone) gives a lot of concentric rings, that makes evidential the fact of existence of small-grained inclusions. Deciphering of this electron-diffraction pattern reveals the presence of such elements as residue SiC, Al, Si, as well as inclusions of graphite.

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Precipitation of Kr In Ni at Room Temperature

MRS Proceedings ◽

10.1557/proc-74-345 ◽

1986 ◽

Vol 74 ◽

Cited By ~ 5

Author(s):

R. C. Birtcher ◽

A. S. Liu

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Electron Diffraction ◽

Electron Scattering ◽

Room Temperature ◽

Lattice Parameter ◽

Dark Field ◽

Asymptotic Limit ◽

Transmission Electron ◽

Fluence Dependence

AbstractThe fluence dependence of Kr precipitation in Ni at room temperature has been studied with the aid of Transmission Electron Microscopy. As in other metals, the Kr precipitates in small cavities. Electron diffraction demonstrates that the Kr precipitates are solid, fcc crystals aligned with each other and the Ni lattice. The trends are similar to those observed for Kr precipitation in Al at room temperature. The average Kr lattice parameter, determined from the electron diffraction, increases with increasing Kr fluence from 0.515 nm to an asymptotic value of 0.545 nm. The asymptotic limit is due to the melting of the larger Kr precipitates. The mismatch between the Kr and Ni lattices is as large as 55%. Diffuse electron scattering was observed from large, liquid Kr precipitaes. This occurs for Kr fluences above 5.1020 Kr+ m-2 in Ni and above 2.5.1020 Kr+ m-2 in Al. At room temperature, the largest solid Kr precipitate observed in dark field images was 8.3 nm in diameter compared to 4.7 nm in Al. The larger precipitates are liquid or gas. The solid Kr metals at the same lattice parameter in both Ni and Al suggesting that the melting is thermodynamic in nature and independent of the host material.

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Microstructure evolution of Ca0.33CoO2 thin films investigated by high-angle annular dark-field scanning transmissionelectron microscopy

Journal of Materials Research ◽

10.1557/jmr.2009.0020 ◽

2009 ◽

Vol 24 (1) ◽

pp. 279-287 ◽

Cited By ~ 4

Author(s):

Rong Huang ◽

Teruyasu Mizoguchi ◽

Kenji Sugiura ◽

Shin-ichi Nakagawa ◽

Hiromichi Ohta ◽

...

Keyword(s):

Thin Films ◽

Electron Diffraction ◽

Solid Phase ◽

Spherical Aberration ◽

Amorphous Layer ◽

Dark Field ◽

High Angle ◽

Orientation Relationships ◽

Transmission Electron ◽

Annular Dark Field

Microstructures of epitaxial Ca0.33CoO2 thin films, which were grown on m plane and c(0001) plane of α–Al2O3 by the reactive solid-phase epitaxy (R-SPE) method and the subsequent ion-exchange treatment, were investigated in detail by using selected-area electron diffraction, high-resolution transmission electron microcopy, spherical-aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (Cs-corrected HAADF-STEM), and electron energy-loss spectroscopy (EELS). Detailed electron diffraction analyses reveal that the orientation relationships between Ca0.33CoO2 thin film and substrate are and , having an angle of about 43° with for the film deposited on m plane, and and for the film deposited on c(0001) plane though a Ca–Al–O amorphous layer formed between them. CoO seed layer near the interface and residual Co3O4 phase inside the films were observed and identified by HAADF-STEM and EELS in both samples. Such microstructural configuration indicates that the processes of film growth during R-SPE are (i) oxidation of CoO into Co3O4 with residual CoO layer near the interface and (ii) intercalation of Na+ layer into Co3O4 to achieve the layered NaxCoO2 film while forming Na–Al–O amorphous layer at the interface.

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