Epitaxial Growth and Structure of Cubic and Pseudocubic Perovskite Films on Perovskite Substrates

1995 ◽  
Vol 401 ◽  
Author(s):  
P. A. Langjahr ◽  
T. Wagner ◽  
M. RÜhle ◽  
F. F. Lange
Keyword(s):  
Electron Microscopy ◽  
Epitaxial Growth ◽  
Lattice Mismatch ◽  
High Resolution Electron Microscopy ◽  
Lattice Parameter ◽  
Ternary Oxide ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Resolution Electron

AbstractCubic and pseudocubic perovskite films on perovskite substrates are used to study the influence of the lattice mismatch on the epitaxial growth of thin films on substrates of the same structure. For the growth of the films, a metalorganic decomposition route (MOD) using 2-ethylhexanoates and neodecanoates as precursors, was developed. The decomposition of the precursors was investigated with thermogravimetric analysis (TGA) and x-ray diffraction (XRD). The films were spin-coated on (001)-oriented SrTiO3- and LaAlO3-substrates, pyrolyzed and afterwards annealed between 600°C and 1200°C. XRD-nvestigations and conventional transmission electron microscopy (CTEM) show, that epitaxial films with the orientation relationship [100](001) film ║ [100](001) substrate can be grown. With XRD, it could be shown, that not only ternary oxide films (SrZrO3, BaZrO3 and BaCeO3), but also perovskite solid solution films (SrTi0.5Zr0.5O3and BaCe0.5Zr0.5O3) can be prepared. Strong interdiffusion, detected by a shift of the film lattice parameter towards the substrate lattice parameter was found in SrZrO3- and BaZrO3-films on SrTiO3, annealed at temperatures above 1050°C. High resolution electron microscopy (HREM) studies of SrZrO3 on SrTiO3 show that a crystalline semicoherent interface with a periodical array of misfit dislocations is present.

HIGH RESOLUTION ELECTRON MICROSCOPE STUDY OF CdTe-Cd0.6Mn0.4 Te SUPERLATTICES

1985 ◽  
Vol 56 ◽  
Author(s):  
C. CHOI ◽  
N. OTSUKA ◽  
L. A. KOLODZIEJSKI ◽  
R. L. GUNSHOR-a
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Phase Contrast ◽  
Electron Microscope Study ◽  
Lattice Mismatch ◽  
Thick Layer ◽  
High Resolution Electron Microscopy ◽  
Misfit Dislocations ◽  
Resolution Electron ◽  
High Resolution Electron Microscope

AbstractStructures of CdTe-Cd0.6Mn0.4Te superlattices which are caused by the lattice mismatch between suterlattice layers have been studied by high resolution electron microscopy (HREM). In thin-layer superlattices, the crystal lattice in each layeris elastically distorted, resulting in the change of the crystal symmetry from cubic to rhombohedral. The presence of the small rhombohedral distrotion has been confirmed through a phase contrast effect in HREM images. In a thick-layer superlattice, the lattice mismatch is accommodated by dissociated misfit dislocations. Burgers vectors of partial misfit dislocations have been identified from the shift of lattice fringes in HREM images.

Transmission electron microscopy observation in a liquid-phase-sintered SiC with oxynitride glass

2001 ◽  
Vol 16 (8) ◽  
pp. 2189-2191 ◽  
Author(s):  
Guo-Dong Zhan ◽  
Mamoru Mitomo ◽  
Young-Wook Kim ◽  
Rong-Jun Xie ◽  
Amiya K Mukherjee
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
High Resolution Electron Microscopy ◽  
Nitrogen Atmosphere ◽  
X Ray Diffraction ◽  
Sintering Additive ◽  
Transmission Electron ◽  
High Annealing ◽  
Resolution Electron ◽  
Oxynitride Glass

Using a pure α–SiC starting powder and an oxynitride glass composition from the Y–Mg–Si–Al–O–N system as a sintering additive, a powder mixture was hot-pressed at 1850 °C for 1 h under a pressure of 20 MPa and further annealed at 2000 °C for 4 h in a nitrogen atmosphere of 0.1 MPa. High-resolution electron microscopy and x-ray diffraction studies confirmed that a small amount of β–SiC was observed in the liquid-phase-sintered α–SiC with this oxynitride glass, indicating stability of β–SiC even at high annealing temperature, due to the nitrogen-containing liquid phase.

Transmission electron microscopy study of Co/Pd and Co/Au multilayers

1993 ◽  
Vol 8 (5) ◽  
pp. 1019-1027 ◽  
Author(s):  
F. Hakkens ◽  
A. De Veirman ◽  
W. Coene ◽  
Broeder F.J.A. den
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Columnar Structure ◽  
Electron Microscopy Study ◽  
Misfit Dislocations ◽  
Transmission Electron ◽  
Resolution Electron

The structure of Co/Pd and Co/Au (111) multilayers is studied using transmission electron microscopy and high resolution electron microscopy. We focused on microstructure, atomic stacking (especially at the interfaces), and coherency, as these are structural properties that have considerable magnetic effects. A columnar structure with a strong curvature of the multilayer influenced by substrate temperature during growth is observed. High resolution imaging shows numerous steps at the interfaces of the multilayer structure and the presence of misfit dislocations. In bright-field images, periodic contrast fringes are observed at these interfaces as the result of moiré interference. These moiré fringes are used to study the misfit relaxation at the interfaces, whereas electron diffraction gives the average relaxation over the whole layer. Both measurements determined that, for Co/Pd as well as Co/Au multilayers, 80–85% of the misfit is relaxed and 20–15% remains in the form of strain, independent of the Co layer thickness in the regime studied.

High-Resolution Electron Microscopy of C60 Clusters

1991 ◽  
Vol 49 ◽  
pp. 1024-1025
Author(s):  
M. M. Disko ◽  
S. K. Behal ◽  
R. D. Sherwood ◽  
F. Cosandey ◽  
P. Lu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Crystallization Rate ◽  
High Resolution Electron Microscopy ◽  
Single Type ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
New Information ◽  
Resolution Electron ◽  
Solvent Type ◽  
Carbon Molecules

Methods for the preparation of significant quantities of C60 clusters separated from carbon soot were recently reported by Krätschmer and co-workers. Evidence that these clusters have the “Buckminsterfullerene” structure with five-fold and six-fold carbon rings on the surface of a sphere (soccer-ball structure) has been provided by several techniques. NMR shows a single type of carbon bonding, and IR peaks consistent with modes characteristic of this system have been identified. Since C60 can be isolated and has stable “graphitic” bonding, it represents a unique opportunity to observe individual stable carbon molecules with transmission electron microscopy in order to test the morphology deduced from other techniques. Also, the study of packing sequences and defect structures in C60 crystals found by x-ray diffraction to have an FCC lattice constant of 1.41 nm provides important new information on variations of crystallization with conditions such as solvent type and crystallization rate.

Ultra Long SiCN Nanowires and SiCN/SiO2 Nanocables: Synthesis, Characterization, and Electrical Property

2008 ◽  
Vol 8 (12) ◽  
pp. 6338-6343
Author(s):  
K. F. Cai ◽  
L. Y. Huang ◽  
A. X. Zhang ◽  
J. L. Yin ◽  
H. Liu
Keyword(s):  
Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Argon Atmosphere ◽  
Quartz Tube ◽  
Catalyst Precursor ◽  
X Ray Diffraction ◽  
Polycrystalline Alumina ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Electron

SiCN nanowires are synthesized by pyrolysis of hexamethyldisilazane (HMDSN) using ferrocene as a catalyst precursor at 1200 °C in a flowing argon atmosphere on the surface of mullite substrate, polycrystalline alumina wafer and quartz tube. In oxygen-contained argon atmosphere, SiCN/SiO2 nanocables are synthesized. The as-synthesized products are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and high-resolution electron microscopy equipped with energy dispersive X-ray spectroscopy. The lengths of the nanowires and nanocables are in the millimeter range. The diameter of the SiCN nanowires grown on mullite substrate and alumina wafer ranges from about 10–70 nm, while that of the nanowires grown on quartz tube surface is in the range of around 7–10 nm. The diameters of the SiCN/SiO2 nanocables are relatively large. A vapor-liquid-solid growth mechanism of the nanostructures is proposed. The electrical resistivity of a single SiCN/SiO2 nanocable is reported for the first time.

Synthesis and Optical Properties of Hollow Spheres Self-Assembled by ZnO Nanocrystals

2011 ◽  
Vol 236-238 ◽  
pp. 2019-2023
Author(s):  
Xiao Min Meng ◽  
Ai Min He
Keyword(s):  
Electron Microscopy ◽  
Hollow Spheres ◽  
High Resolution Electron Microscopy ◽  
X Ray Diffraction ◽  
Benzene Sulfonic Acid ◽  
Zno Nanocrystals ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Dodecyl Benzene Sulfonic Acid ◽  
Self Assembled

Nano-sized hollow spheres self-assembled by ZnO nanocrystals have been prepared by microemulsion method with dodecyl benzene sulfonic acid sodium salt (DBS) as the modifying and protecting agent. The product was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high High-resolution electron microscopy (HRTEM) energy dispersive spectroscopy (EDS) and photoluminescence (PL) spectra. The results showed that the hollow sphere was composed of ZnO nanocrystals. And the PL spectrum showed a different emission at 438 nm. After heated the product, PL emission peak changed. A possible formation mechanism was also proposed.

New Insights on the Morphology of Nanocomposite Prepared by In Situ Emulsion Polymerization

2015 ◽  
Vol 775 ◽  
pp. 170-175
Author(s):  
José Costa de Macêdo Neto ◽  
João Evangelista Neto ◽  
Nayra Reis do Nascimento ◽  
Sheila Contant ◽  
Liliane Maria Ferrareso Lona
Keyword(s):  
Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
X Ray Diffraction ◽  
Nanocomposite Powder ◽  
Thin Sections ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Level Of Details ◽  
High Level

In order to better understand the morphology and properties of polymer nanocomposites it is necessary to conduct their characterization by Transmission Electron Microscopy (TEM). This work shows a technique through which the nanocomposite powder is mixed with a resin, and after cured, thin sections can be obtained by ultramicrotomy. Another technique presented in this work deals with the observation of clay powder in solution. In this work High Resolution Electron Microscopy (HRTEM) was used to obtain images of the nanocomposites and clay. Images with a high level of details were showed. Through the use of such techniques, it was possible to observe two types of clay morphology in polymer matrix and its distribution. The dimensions and hexagonal layers of the natural clay used as nanofiller for the nanocomposite were also observed. The X-ray Diffraction (XRD) was used to investigate the kaolinite and nanocomposite.

Microstructure at the interface between AIN and a Ag–Cu–Ti braze alloy

1990 ◽  
Vol 5 (7) ◽  
pp. 1520-1529 ◽  
Author(s):  
A. H. Carim ◽  
R. E. Loehman
Keyword(s):  
Electron Microscopy ◽  
Thermal Expansion ◽  
Structural Integrity ◽  
Lattice Mismatch ◽  
Braze Alloy ◽  
High Resolution Electron Microscopy ◽  
Nitride Layer ◽  
Orientation Relationships ◽  
Transmission Electron ◽  
Resolution Electron

The joining of aluminum nitride by active metal brazing with a Ag–Cu–Ti foil has been investigated in cross section by transmission electron microscopy. The reaction of AIN with the braze alloy results in the formation of continuous TiN and (Ti, Cu, Al)6N (η-phase) layers at the interface. AIN grains at the interface often display arrays of dislocations, presumably arising from thermal expansion mismatch between the AIN and the TiN (the coefficients of thermal expansion are 43 ⊠ 10−7/°C and 80 ⊠ 10−7/°C, respectively). The adjoining TiN contains small Cu precipitates and may also contain numerous defects. Titanium preferentially penetrates the AIN grain boundaries, resulting in finger-like TiN intrusions into the substrate, which sometimes cover entire AIN grains in a TiN shell. On the other side of the TiN, a continuous layer of equiaxed, defect-free η–nitride grains is found. Beyond this η–nitride layer is the remaining mixture of metallic Ag and Cu. High-resolution electron microscopy demonstrates that the AIN–TiN and TiN–η boundaries are abrupt and contain no additional crystalline or amorphous intervening phases. Particular orientation relationships are occasionally observed at the AIN–TiN interface; these are not always the ones that produce the minimum lattice mismatch. The implications of the observed morphology with respect to the reaction sequence, transitional phases, and structural integrity of the joint are discussed.

Characterization of ErAs/GaAs and GaAs/ErAs/GaAs Structures

1989 ◽  
Vol 160 ◽  
Author(s):  
Jane G. Zhu ◽  
Chris J. Palmstrøm ◽  
Suzanne Mounier ◽  
C. Barry Carter
Keyword(s):  
Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Gaas Layer ◽  
Misfit Dislocations ◽  
Weak Beam ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Small Grains ◽  
Major Defect

AbstractA series of ErAs/GaAs and GaAs/ErAs/GaAs epilayers have been grown on (100) GaAs substrates by molecular-beam epitaxy. Misfit dislocations at the ErAs/GaAs interface have been analyzed using the weak-beam technique of transmission electron microscopy. The microstructure of GaAs/ErAs/GaAs layers have been characterized using conventional and high-resolution electron microscopy. Twinning inside the upper GaAs layer is the major defect. Although the desired epitactic (100) GaAs on (100) ErAs does dominate, small grains of GaAs with (111) or {122} orientations have been observed at the GaAs/ErAs heterojunction.

Epitaxial Growth of BaF2 on Semiconductor Substrates

1982 ◽  
Vol 18 ◽  
Author(s):  
J. M. Phillips ◽  
L. C. Feldman ◽  
J. M. Gibson ◽  
M. L. Mcdonald
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Substrate Temperature ◽  
Epitaxial Growth ◽  
Lattice Mismatch ◽  
The Other ◽  
Misfit Dislocations ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Semiconductor Substrates

We used Rutherford backscattering and channeling and transmission electron microscopy (TEM) to study the epitaxial growth of BaF2 vacuum deposited onto InP(100), InP(111), Ge(100) and Ge(111). We observed no epitaxy in BaF2 on Ge(100). The other three cases all show epitaxy, with quality ranging from poor for BaF2 on InP(111) through fair for BaF2 on InP(100) to excellent for BaF2 on Ge(111). Epitaxial quality depends strongly on substrate temperature for BaF2 on Ge(l11). TEM analysis indicates that there are neither misfit dislocations nor coherence at the BaF2–Ge(111) interface in spite of the 9.1% lattice mismatch.

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