Self-Organized Composition Modulation In Omvpe Ga1−xInxAsySb1−y/GaSb Epitaxial Heterostructures

1999 ◽  
Vol 583 ◽  
Author(s):  
Y-C. Chen ◽  
V. Bucklen ◽  
K. Rajan ◽  
C. A. Wang ◽  
G. W. Charache ◽  
...  
Keyword(s):  
Cross Section ◽  
Three Dimensional ◽  
Component Composition ◽  
Organometallic Vapor Phase Epitaxy ◽  
Composition Modulation ◽  
Self Organized ◽  
Transmission Electron ◽  
Epitaxial Heterostructures ◽  
20 Nm ◽  
Lattice Matched

AbstractMicrostructures of lattice-matched Ga1−xInxAsySb1−y grown by organometallic vapor phase epitaxy (OMVPE) on (100) 6°→ (111)B GaSb substrates have been examined in detail by transmission electron microscopy. A three-dimensional self-organized composition modulation (SOCM) microstructure was found with an orientation inclined 10 degrees to the surface orientation when viewed in (011) cross-section. The periodicity of the SOCM increased from ˜13 nm to 20 nm, as x increased from 0.1 to 0.2 while the orientation of the SOCM remained the same. The fact that the orientation was not sensitive to the component composition indicated that substrate misorientation plays a major role in deciding this SOCM orientation. This may open fabrication opportunities for three-dimensional natural superlattices by engineering on the substrate misorientation.

scholarly journals Self-Organized Superlattices in GaInAsSb Grown on Vicinal Substrates

2003 ◽  
Vol 794 ◽  
Author(s):  
C.A. Wang ◽  
C.J. Vineis ◽  
D.R. Calawa
Keyword(s):  
Deposition Temperature ◽  
Alloy Composition ◽  
Growth Conditions ◽  
Composition Modulation ◽  
Compositional Modulation ◽  
Complex Interactions ◽  
Self Organized ◽  
Natural Superlattice ◽  
Lateral Extent ◽  
Lattice Matched

ABSTRACTSelf-organized superlattices are observed in GaInAsSb epilayers grown lattice matched to vicinal GaSb substrates. The natural superlattice (NSL) is oriented at a slight angle of about 4° with respect to the vicinal (001) GaSb substrate. This vertical composition modulation is detected at the onset of growth. Layers in the NSL are continuous over the lateral extent of the substrate. Furthermore, the NSL persists throughout several microns of deposition. The NSLs have a period ranging from 10 to 30 nm, which is dependent on deposition temperature and GaInAsSb alloy composition. While the principle driving force for this type of phase separation is chemical, the mechanism for the self-organized microstructure is related to local strains associated with surface undulations. By using a substrate with surface undulations, the tilted NSL can be induced in layers with alloy compositions that normally do not exhibit this self-organized microstructure under typical growth conditions. These results underscore the complex interactions between compositional modulation and morphological perturbations.

Self-Healing and Self-Organized Gold Nanoparticle Films at a Water/Organic Solvent Interface

2006 ◽  
Vol 6 (1) ◽  
pp. 130-134 ◽  
Author(s):  
Olivier Balmes ◽  
Jan-Olov Bovin ◽  
Jan-Olle Malm
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Organic Solvent ◽  
Continuous Production ◽  
Self Healing ◽  
Self Organized ◽  
Transmission Electron ◽  
20 Nm

Gold nanoparticles (5 nm and 20 nm) have been synthesized and stabilized with mercaptoundecanol. These particles, although insoluble in water or common organic solvents, spread as a thin film at the liquid–liquid interface between a water phase and an organic phase. Films of these gold nanoparticles have been observed both by conventional transmission electron microscopy of deposited samples and by cryo-transmission electron microscopy of plunge-frozen samples. The film can be monolayered and extend over centimeter-sized areas. The particle films spontaneously re-assemble and self-organize at the interface when disrupted. This self-healing capacity of the film should make it possible to build a device for continuous production and deposition of the film.

Structure and mechanical properties of epitaxial TiN/V0.3Nb0.7N(100) superlattices

1994 ◽  
Vol 9 (6) ◽  
pp. 1456-1467 ◽  
Author(s):  
P.B. Mirkarimi ◽  
S.A. Barnett ◽  
K.M. Hubbard ◽  
T.R. Jervis ◽  
L. Hultman
Keyword(s):  
Elastic Modulus ◽  
Lattice Mismatch ◽  
X Ray Diffraction ◽  
Crystalline Perfection ◽  
Composition Modulation ◽  
Superlattice Structure ◽  
Transmission Electron ◽  
Identical Composition ◽  
Coherency Strains ◽  
Lattice Matched

Epitaxial TiN/V0.3Nb0.7N superlattices with a 1.7% lattice mismatch between the layers were grown by reactive magnetron sputtering on MgO(001) substrates. Superlattice structure, crystalline perfection, composition modulation amplitudes, and coherency strains were studied using transmission electron microscopy and x-ray diffraction. Hardness H and elastic modulus were measured by nanoindentation. H increased rapidly with increasing Λ, peaking at H values ≍75% greater than rule-of-mixtures values at Λ ≍ 6 nm, before decreasing slightly with further increases in Λ. A comparison with previously studied lattice-matched TiN/V0.6Nb0.4N superlattices, which had nearly identical composition modulation amplitudes, showed a similar H variation, but a smaller H enhancement of ≍50%. The results suggest that coherency strains, which were larger for the mismatched TiN/V0.3Nb0.7N superlattices, were responsible for the larger hardness enhancement. The results are discussed in terms of coherency strain theories developed for spinodally decomposed materials. Nanoindenter elastic modulus results showed no significant anomalies.

Structure and Nanocrystallites of Ni and NiO Three Dimensional Ordered Macromeshes

2001 ◽  
Vol 703 ◽  
Author(s):  
W.L. Zhou ◽  
L. Xu ◽  
A.A. Zakhidov ◽  
R.H. Baughman ◽  
J.B. Wiley
Keyword(s):  
Electron Microscope ◽  
Three Dimensional ◽  
Temperature Treatment ◽  
Inverse Opal ◽  
Preferential Growth ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Ordered Macroporous ◽  
Nio Nanocrystals ◽  
20 Nm

ABSTRACTThree dimensional Ni and NiO inverse opal macromeshes were characterized by scanning electron microscope (SEM) and transmission electron microscope (SEM). The octahedral cubes of the macroporous Ni were found mostly grown as single crystals with staking faults and microtwins. There was no preferential growth of these cubes as determined by selected area diffraction pattern (SADP). Some NiO nanocrystals with size of about 5 nm were formed on the surface of inverse Ni opal membrane during etching away of silica spheres. The oxidation of Ni mesh turned it into NiO macromesh with grain size of about 20 nm at 550°C. The nanocrystalline NiO mesh is suitable for further fabrication of three dimensional nanobeads. By annealing the meshes at 650°C, the NiO nanograins grew to a size of over 50 nm. This three dimensional ordered macroporous structure with higher temperature treatment is considered as stable and important for further application.

Three-Dimensional Reconstruction of Erythrocytes Using the Novel Method For Corrective Realignment of the Transmission Electron Microscopy Cross-Section Images

2018 ◽  
Vol 24 (6) ◽  
pp. 676-683
Author(s):  
Yuzhou Fan ◽  
Djordje Antonijević ◽  
Xing Zhong ◽  
Vladimir S. Komlev ◽  
Zhiyu Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
3D Model ◽  
Three Dimensional ◽  
Blood Rheology ◽  
The Body ◽  
Transmission Electron ◽  
Detailed Kinetics ◽  
Morphological Relationship

AbstractThe detailed kinetics study of erythrocyte deformability is useful for the early diagnosis of blood diseases and for monitoring the blood rheology. Present solutions for a three-dimensional (3D) reconstruction of erythrocytes has a limited potential. This study aimed to use erythrocyte transmission electron images (ETIs) to evaluate the morphological relationship between adjacent ETIs and generate erythrocytes 3D model. First, ultrathin serial sections of skeletal muscle tissue were obtained using an ultramicrotome. Further, the set of ETIs in a capillary were captured by transmission electron microscopy. The images were aligned by translations and rotations using custom software to optimize the morphological relationship between adjacent ETIs. These coordinate transformations exploit the unique principal axis of inertia of each image to define the body coordinate system and hence provide the means to accurately reconnect the adjacent ETIs. The sum of the distances between the corresponding points on the boundary of adjacent ETIs was minimized and, further, was optimized by using physiological relationship between the adjacent ETIs. The analysis allowed to define precise virtual relationship between the adjacent erythrocytes. Finally, extracted erythrocytes’ cross-section images allowed to generate 3D model of the erythrocytes.

Structure of composition-modulated Cu/Ni thin films prepared by electrodeposition

1989 ◽  
Vol 4 (4) ◽  
pp. 755-758 ◽  
Author(s):  
J. Yahalom ◽  
D. F. Tessier ◽  
R. S. Timsit ◽  
A. M. Rosenfeld ◽  
D. F. Mitchell ◽  
...  
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Structure ◽  
Composition Modulation ◽  
Transmission Electron ◽  
Electron Energy Loss ◽  
Multilayered Thin Films

Copper/nickel multilayered thin-films prepared by electrodeposition have been examined in cross section by electron energy loss spectroscopy and high-resolution transmission electron microscopy. The results of the examinations provide the first direct experimental evidence of the large composition modulation across successive layers in the thin-film structure and the coherent nature of Cu/Ni interfaces.

Surface Roughening and Composition Modulation of ZnSe-related II-VI epitaxial films

1996 ◽  
Vol 448 ◽  
Author(s):  
Shigetaka Tomiya ◽  
Hironori Tsukamoto ◽  
Satoshi Itoh ◽  
Kazushi Nakano ◽  
Etsuo Morita ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Surface Reconstruction ◽  
Epitaxial Films ◽  
Surface Roughening ◽  
Force Microscopy ◽  
Composition Modulation ◽  
Atomic Force ◽  
Transmission Electron ◽  
Rich Condition ◽  
Lattice Matched

AbstractWe have investigated ZnSSe and ZnMgSSe epitaxial layers lattice-matched to GaAs (001) substrates grown by molecular beam epitaxy using atomic force microscopy and transmission electron microscopy. Under II-rich conditions with c(2x2) surface reconstruction, surface morphology exhibited corrugation aligned in the [1ī0] direction and composition modulation was observed in the same [1ī0] direction. Under VI-rich condition with (2x1) surface reconstruction, the surface morphology becomes rounded grain-like and composition modulation was not observed. The formation of composition modulation is associated with the surface corrugated structures.

Hardness–depth profile of a carbon-implanted Ti–6Al–4V alloy and its relation to composition and microstructure

2001 ◽  
Vol 16 (8) ◽  
pp. 2321-2335 ◽  
Author(s):  
M. Kunert ◽  
O. Kienzle ◽  
B. Baretzky ◽  
S. P. Baker ◽  
E. J. Mittemeijer
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Cross Section ◽  
Depth Profile ◽  
Constant Load ◽  
Variation Method ◽  
Indentation Modulus ◽  
Transmission Electron ◽  
20 Nm ◽  
Hardness Depth

The variation of mechanical properties (hardness, indentation modulus) within a carbon-implanted region of a Ti–6Al–4V alloy—about 350-nm thick—was, for the first time, related with the microstructure and the chemical composition with a depth accuracy as small as ±20 nm. Microstructure, chemical composition, and mechanical properties of the implanted alloy were determined using transmission electron microscopy, Auger electron spectroscopy, and nanoindentation, respectively. The microstructure within the implanted region contains TiC precipitates, the density of which changes with depth in accordance with the carbon content. The hardness depends on the precipitate density: the maximum hardness occurs at the depth where an almost continuous TiC layer had formed. The depth profiles of hardness and indentation modulus were measured using three different methods: the cross-section method (CSM); the constant-load method (CLM); and the load-variation method (LVM). Only the hardness– depth profile obtained using the CSM, in which the indentations are performed perpendicular to the hardness gradient on a cross section of the specimen, reflects the microstructural variations present in the implanted region.

Resolving the Nanostructure of Self Organized Thin Films using Corrected Scanning Transmission Electron Microscopy.

MRS Advances ◽  
2016 ◽  
Vol 1 (24) ◽  
pp. 1749-1754
Author(s):  
Robert D. Boyd ◽  
Viktor Elofsson ◽  
Kostas Sarakinos
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Plasma Deposition ◽  
Three Dimensional ◽  
Material Structure ◽  
Scanning Transmission Electron ◽  
Self Organized ◽  
Transmission Electron ◽  
Scanning Transmission

ABSTRACTCorrected scanning transmission electron microscopy (STEM) was used to characterise a novel thin film displaying a complex three dimensional nanostructure. The film was prepared by plasma deposition in such a way that it self-organises into layers of silver islands (each with typical dimensions of a few nanometres) within an aluminium nitride matrix. Successful application of STEM imaging and subsequent analysis was able to determine critical information about the material structure, namely island size, shape and crystalline orientation and the detection of island – matrix intermixing. Such information is essential in being able to predict the properties of this material and the approach adopted here is applicable to any similarly structured material.

Three-Dimensional Characterization of BaZrO3 Precipitates in Y1-xGdxBa2Cu3O7-y Prepared by TFA-MOD Using STEM-Tomography

2013 ◽  
Vol 750 ◽  
pp. 48-51
Author(s):  
Takeshi Nishiyama ◽  
Kazuhiro Yamada ◽  
Ryo Teranishi ◽  
Kenji Kaneko ◽  
Takeharu Kato ◽  
...  
Keyword(s):  
Electron Tomography ◽  
Ion Beam ◽  
Three Dimensional ◽  
Deposition Process ◽  
Transmission Electron ◽  
Large Numbers ◽  
Elemental Analyses ◽  
Metal Organic ◽  
20 Nm

Y1-xGdxBa2Cu3O7-yfilm with BaZrO3was fabricated on CeO2buffered LaMnO3/ion beam assisted deposition MgO/Gd2Zr2O7/Hastelloy C276TMsubstrates by the trifluoroacetates metal organic deposition process, whose microstructural and elemental analyses were performed by transmission electron microscopy. Y1-xGdxBa2Cu3O7-yfilm with the thickness about 700 nm was found composed of c-axis oriented grains and large numbers of randomly oriented precipitates, such as (Y,Gd)2Cu2O5, CuO and BaZrO3. (Y,Gd)2Cu2O5and CuO precipitates were heterogeneously dispersed in the Y1-xGdxBa2Cu3O7-ymatrix with their sizes ranging between 100 and 200 nm, and BaZrO3precipitates were uniformly dispersed with their sizes ranging between 10 and 20 nm. Electron tomography with elemental information was performed further to reveal the three-dimensional information of BaZrO3 precipitates.

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