TEM Study of (015) Growth Twins in The Bi-Sr-Ca-Cu-O Superconductors Obtained by Melt Quench Technique

1991 ◽  
Vol 238 ◽  
Author(s):  
Ohnishi N ◽  
Sankararaman M ◽  
Sato H
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Grain Growth ◽  
Twin Boundary ◽  
Twin Structure ◽  
Transmission Electron ◽  
Twinning Plane ◽  
Incommensurate Modulation ◽  
New Type

ABSTRACTA new type of twin structure is found to exist quite commonly in the Bi2Sr2CaCu2O8+δ superconductor obtained by annealing melt quenched amorphous precursors. From transmission electron microscopy and electron diffraction, the twinning plane is determined to be the (015) plane (disregarding the period of incommensurate modulation in the b-direction). Further, the twin boundary is found to be coherent with a specific coincidence condition. The analysis of the morphologies indicates that the twins nucleate at the early stages of the grain growth in these materials.

Phase Formation and Hydrogen Ordering in Yttrium-Hydrogen System

2009 ◽  
Vol 1216 ◽  
Author(s):  
Ke Wang ◽  
Jason Hattrick-Simpers ◽  
Leonid Bendersky
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Electron Diffraction ◽  
Twin Boundaries ◽  
Sapphire Substrates ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
New Type

AbstractPhase transformations in epitaxial yttrium films grown on (0001)Ti//(0001)Al2O3 Ti-buffered sapphire substrates and hydrogenated for 10 min were characterized using transmission electron microscopy. After hydrogen charging, dense twin lamellae form during α(Y(H))-to-β(YH2) phase transition with twin boundaries predominately parallel to the interface between Y and a substrate. High densities of Shockley partial dislocations are present at the twin boundaries, their glides during phase transformation are responsible for the formation of twin lamellae. Electron diffraction from YH2 phase shows superlattice reflections, which suggests a new type of ordering on octahedral interstitial sites.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

Where are the geometrically necessary dislocations accommodating small imprints?

2009 ◽  
Vol 24 (3) ◽  
pp. 647-651 ◽  
Author(s):  
M. Rester ◽  
C. Motz ◽  
R. Pippan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Twin Boundary ◽  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Copper Single Crystals ◽  
Backscatter Diffraction ◽  
Small Misorientation

Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analyses of small indentations in copper single crystals exhibit only slight changes of the crystal orientation in the surroundings of the imprints. Far-reaching dislocations might be the reason for these small misorientation changes. Using EBSD and TEM technique, this work makes an attempt to visualize the far-propagating dislocations by introducing a twin boundary in the vicinity of small indentations. Because dislocations piled up at the twin boundary produce a misorientation gradient, the otherwise far-propagating dislocations can be detected.

Laser-Induced Oxidation and Crystallization of Thin Amorphous Sputtered Cr Films

1983 ◽  
Vol 29 ◽  
Author(s):  
M. I. Birjega ◽  
C. A. Constantin ◽  
M. Dinescu ◽  
I. Th. Florescu ◽  
I. N. Mihailescu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Laser Irradiation ◽  
Dwell Time ◽  
Free Standing ◽  
Transmission Electron Diffraction ◽  
Oxidation Processes ◽  
Transmission Electron ◽  
Power Densities

ABSTRACTThe crystallization and oxidation processes of thin, free-standing (FS), sputtered Cr films under the action of cw CO2 laser irradiation were studied by transmission electron microscopy (TEM) and transmission electron diffraction (TED). The crystallization is induced at power densities above 28.65 W cm−2, dwell time of 1 s, and the oxidation at power densities of 48.1 W cm−2 and longer dwell times.

Lattice Defects in Epitaxial Ba2Bi4Ti5O18 Thin Films Grown by Pulsed Laser Deposition Onto LaNiO3 Bottom Electrodes

2000 ◽  
Vol 623 ◽  
Author(s):  
N.D. Zakharov ◽  
A.R. James ◽  
A. Pignolet ◽  
S. Senz ◽  
D. Hesse
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Stacking Sequence ◽  
Rectangular Shape ◽  
Transmission Electron ◽  
Single Well ◽  
New Type

AbstractEpitaxial, ferroelectric Ba2Bi4Ti5O18 films grown on LaNiO3/CeO2/ZrO2:Y2O3 epitaxial layers on Si(100) are investigated by cross-section high-resolution transmission electron microscopy (HRTEM). The films are perfectly oriented and consist of well-developed grains of rectangular shape. The grain boundaries are strained and contain many defects, especially a new type of defect, which can be described as a staircase formed by repeated lattice shifts of Δ ∼ c/12 ∼ 4.2 Å in the [001] direction. This repeated shift results in seemingly bent ribbons of stacked Bi2O2 planes, involving, however, individual Bi2O2 planes which remain strongly parallel to the (001) plane. These defects contain an excess of bismuth. Other defects found in the grain interior include mistakes in the stacking sequence originating from the presence of single, well-oriented, non-stoichionietric layers intergrown with the stoichiometric Ba2Bi4Ti5O18 film matrix.

Structural transformation of a kaolinite and calcite mixture to gehlenite and anorthite

2003 ◽  
Vol 18 (2) ◽  
pp. 475-481 ◽  
Author(s):  
Karfa Traoré ◽  
Philippe Blanchart
Keyword(s):  
Electron Microscopy ◽  
Phase Diagram ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Low Temperature ◽  
Orientation Relationship ◽  
Interlayer Spacing ◽  
Direct Transition ◽  
Transmission Electron ◽  
Successive Phase

Kaolinite mixed with calcite was sintered at low temperature (1100 °C; 5 °C/min). The successive phase transformations are metakaolinite to gehlenite and then anorthite, although the available phase diagram indicates a direct anorthite recrystallization. Transmission electron microscopy and electron diffraction studies of nanocrystallites revealed that the transformation path is favored by the structural similarities of phases. In particular, the pseudolayers of gehlenite have a major orientation relationship with the initial metakaolinite layers. The gehlenite axis, [001]G, is parallel to the metakaolinite axis, [001]A. This direct transition is favored by the existence of Si tetrahedral units and 4–fold–coordinated Al in both structures. Ca atoms, initially in the interlayer spacing of metakaolinite, remain in the interlayers of gehlenite. During the second transformation step, anorthite recrystallizes from gehlenite with axis [020]A parallel to [210]G. It is proposed that this orientation relationship is favored by the orientation and shape of Ca-atom channels through both structures, along [001]G and [100]A axes.

scholarly journals Probing planar defects in nanoparticle superlattices by 3D small-angle electron diffraction tomography and real space imaging

Nanoscale ◽  
2014 ◽  
Vol 6 (22) ◽  
pp. 13803-13808 ◽  
Author(s):  
Arnaud Mayence ◽  
Dong Wang ◽  
German Salazar-Alvarez ◽  
Peter Oleynikov ◽  
Lennart Bergström
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Real Space ◽  
Diffraction Tomography ◽  
Planar Defects ◽  
Pd Nanoparticle ◽  
Transmission Electron ◽  
Nanoparticle Superlattices ◽  
Microscopy Techniques

Planar defects in Pd nanoparticle superlattices were revealed by a combination of real and reciprocal space transmission electron microscopy techniques. 3D electron diffraction tomography was extended to characterize mesoscale imperfections.

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.

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