In Stlo High Resolution Electron Microscopy for Interface Studies

1986 ◽  
Vol 82 ◽  
Author(s):  
M. A. Parker ◽  
R. Sinclair
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Solid Phase ◽  
High Resolution Electron Microscopy ◽  
Kinetic Measurements ◽  
High Voltage Electron Microscopy ◽  
Interface Reactions ◽  
Voltage Electron ◽  
Transmission Electron ◽  
Resolution Electron

In situ kinetic measurements on the rate of solid—phase epitaxial regrowth of silicon in a conventional transmission electron microscope are described. The data compare well with those established for the sane material by high voltage electron microscopy and by Rutherford backscattering spectroscopy. High—resolution imaging at the same time provides direct information on atomic mechanisms. It is anticipated that this will beccme a more highly developed procedure in due course, especially for studies of interface reactions.

Studies of Material Reactions by In Situ High-Resolution Electron Microscopy

MRS Bulletin ◽  
1994 ◽  
Vol 19 (6) ◽  
pp. 26-31 ◽  
Author(s):  
Robert Sinclair
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Atomic Scale ◽  
Ex Situ ◽  
New Materials ◽  
Kinetic Measurements ◽  
Transmission Electron ◽  
Resolution Electron

Processing has always been a key component in the development of new materials. Basic scientific understanding of the reactions and transformations that occur has obvious importance in guiding progress. Invaluable insight can be provided by observing the changes during processing, especially at high magnification by in situ microscopy. Now that this can be achieved at the atomic level by using high-resolution electron microscopy (HREM), atomic behavior can be seen directly. Accordingly, many deductions concerning reactions in materials at the atomic scale are possible.The purpose of this article is to illustrate the level reached by in situ HREM. The essential procedure is to form a high-resolution image of a standard transmission electron microscope (TEM) sample and then to alter the structure by some means in a controlled manner, such as by heating. Continual recording on videotape allows subsequent detailed analysis of the behavior, even on a frame-by-frame (1/30 second) basis. The most obvious advantage is to follow the atomic rearrangements directly in real time. However, in addition, by continuous recording no stages in a reaction are missed, which can often occur in a series of conventional ex situ annealed samples because of the limited number of samples that can realistically be examined by HREM. One can be sure that the same reaction, in the same area, is being studied. Furthermore, by changing the temperature systematically, extremely precise kinetic measurements can be made (e.g., for activation energies and kinetic laws) and the whole extent of a material transformation can be investigated in one sample, something that would take months of work if studied conventionally. The information provided by in situ HREM is often unique and so it can become an important technique for fundamental materials investigations.

High-resolution Electron Microscopy of defects in Ni3Al

1989 ◽  
Vol 47 ◽  
pp. 302-303
Author(s):  
M. J. Mills
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Theoretical Models ◽  
High Resolution Electron Microscopy ◽  
Current Application ◽  
Voltage Electron ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Electron Microscopes ◽  
Anti Phase Boundary

The improved resolution of the latest generation of intermediate voltage electron microscopes makes possible the direct study of the atomic structure of defects in close-packed metals and alloys. Of particular technological interest are several classes of intermetallic compounds which exhibit desirable mechanical properties at higher temperatures. This paper demonstrates the current application of high resolution transmission electron microscopy (HRTEM) to the study of dislocation cores and interfaces in nickel-based alloys, and the implications of the observations in terms of models of deformation and fracture.Several intermetallic alloys with the L12 (Cu3Au) structure exhibit an anomalous increase in the flow stress as a function of temperature. The theoretical models that have been proposed to explain this behavior are based upon consideration of a thermally activated cross slip of screw dislocations from {111} to {010}. These models assume that the dissociation of the a superlattice (SL) dislocation occurs by the formation of an anti-phase boundary (ABP) which is bounded by two a/2 superpartial (SP) dislocations with parallel Burgers vectors.

Atomic structure imaging of the Si/SiO2 interface with high-resolution electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 390-391
Author(s):  
J.L. Batstone ◽  
J.M. Gibson ◽  
Alice.E. White ◽  
K.T. Short
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Atomic Structure ◽  
High Resolution Electron Microscopy ◽  
Medium Voltage ◽  
Voltage Electron ◽  
Resolution Electron ◽  
Structural Image ◽  
Electron Microscopes ◽  
Point To Point

High resolution electron microscopy (HREM) is a powerful tool for the determination of interface atomic structure. With the previous generation of HREM's of point-to-point resolution (rpp) >2.5Å, imaging of semiconductors in only <110> directions was possible. Useful imaging of other important zone axes became available with the advent of high voltage, high resolution microscopes with rpp <1.8Å, leading to a study of the NiSi2 interface. More recently, it was shown that images in <100>, <111> and <112> directions are easily obtainable from Si in the new medium voltage electron microscopes. We report here the examination of the important Si/Si02 interface with the use of a JEOL 4000EX HREM with rpp <1.8Å, in a <100> orientation. This represents a true structural image of this interface.

High Resolution Transmission Electron Microscopy of an automobile catalytic converter

1990 ◽  
Vol 48 (4) ◽  
pp. 242-243
Author(s):  
Jan-Olle Malm ◽  
Jan-Olov Bovin
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Catalytic Converter ◽  
Active Material ◽  
Image Intensifier ◽  
High Resolution Electron Microscopy ◽  
Detailed Knowledge ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Atomic Surface

Understanding of catalytic processes requires detailed knowledge of the catalyst. As heterogeneous catalysis is a surface phenomena the understanding of the atomic surface structure of both the active material and the support material is of utmost importance. This work is a high resolution electron microscopy (HREM) study of different phases found in a used automobile catalytic converter.The high resolution micrographs were obtained with a JEM-4000EX working with a structural resolution better than 0.17 nm and equipped with a Gatan 622 TV-camera with an image intensifier. Some work (e.g. EDS-analysis and diffraction) was done with a JEM-2000FX equipped with a Link AN10000 EDX spectrometer. The catalytic converter in this study has been used under normal driving conditions for several years and has also been poisoned by using leaded fuel. To prepare the sample, parts of the monolith were crushed, dispersed in methanol and a drop of the dispersion was placed on the holey carbon grid.

Structure of InAs Quantum Dots in Si Matrix Investigated by High Resolution Electron Microscopy

1999 ◽  
Vol 571 ◽  
Author(s):  
N. D. Zakharov ◽  
P. Werner ◽  
V. M. Ustinov ◽  
A.R. Kovsh ◽  
G. E. Cirlin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Critical Thickness ◽  
High Resolution Electron Microscopy ◽  
Geometrical Parameters ◽  
Inas Quantum Dots ◽  
Temperature Growth ◽  
Transmission Electron ◽  
Resolution Electron

ABSTRACTQuantum dot structures containing 2 and 7 layers of small coherent InAs clusters embedded into a Si single crystal matrix were grown by MBE. The structure of these clusters was investigated by high resolution transmission electron microscopy. The crystallographic quality of the structure severely depends on the substrate temperature, growth sequence, and the geometrical parameters of the sample. The investigation demonstrates that Si can incorporate a limited volume of InAs in a form of small coherent clusters about 3 nm in diameter. If the deposited InAs layer exceeds a critical thickness, large dislocated InAs precipitates are formed during Si overgrowth accumulating the excess of InAs.

Silicon-Sapphire Interface: A High Resolution Electron Microscopy Study

1980 ◽  
Vol 2 ◽  
Author(s):  
Fernando A. Ponce
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Silicon Layer ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Resolution Limit ◽  
High Concentration ◽  
Transmission Electron ◽  
Resolution Electron

ABSTRACTThe structure of the silicon-sapphire interface of CVD silicon on a (1102) sapphire substrate has been studied in crøss section by high resolution transmission electron microscopy. Multibeam images of the interface region have been obtained where both the silicon and sapphire lattices are directly resolved. The interface is observed to be planar and abrupt to the instrument resolution limit of 3 Å. No interfacial phase is evident. Defects are inhomogeneously distributed at the interface: relatively defect-free regions are observed in the silicon layer in addition to regions with high concentration of defects.

High Resolution Electron Microscopy Observations About The Interface Structure In A Ti/TiN Multilayer Material

1991 ◽  
Vol 238 ◽  
Author(s):  
X. G. Ning ◽  
L. P. Guo ◽  
R. F. Huang ◽  
J. Gong ◽  
B. H. Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Orientation Relationship ◽  
High Resolution Electron Microscopy ◽  
Interface Structure ◽  
Multilayer Material ◽  
Transition Layers ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Specific Orientation

ABSTRACTThe interface structure in a Ti/TiN multilayer material has been investigated by high resolution transmission electron microscopy (HRTEM). It was shown that the α-Ti and β-TiN layers consisted of many cylindrical crystals growing along the close packed directions normal to the surface of a stainless steel. There existed specific orientation relationship at the Ti/TiN interfaces without transition layers: (111)TiN ‖ (001)Ti, [110]TiN ‖ [100]Ti. However there was no such orientation relationship at the Ti/TiN interfaces with TixN (x >1) transition layers.

Combined Use of Small Angle Neutron Scattering (Sans) and (Conventional and High Resolution) Electron Microscopy for the Characterization of Early Stages of Ordering and Phase Separation in Ni-Ti

1986 ◽  
Vol 82 ◽  
Author(s):  
A. Cerri ◽  
R. Schmelczer ◽  
P. Schwander ◽  
G. Kostorz ◽  
A.F. Wright
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Tem Analysis ◽  
Zone Formation ◽  
Early Stages ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Combined Use ◽  
Integrated Intensity

ABSTRACTThe decomposition of Ni ∼ 11.5 at.% Ti single crystals was studied for an ageing temperature of 540°C. In this alloy, coherent ordered zones of γ′-Ni3Ti (Cu3Au structure) are formed prior to the stable n precipitates. The early stages of zone formation were investigated by in-beam SANS and transmission electron microscopy (TEM). Electron diffraction, high resolution electron microscopy, TEM analysis of dislocation arrangements in samples deformed after ageing and X-ray measurements of the integrated intensity at L12 superstructure positions show that ordered regions already appear in quenched samples, whereas compositional changes, as determined by SANS measurements, occur only upon ageing.

High Resolution Transmission Electron Microscopy of Partial States of Oxygen Order in YBa2Cu3Oz

1990 ◽  
Vol 183 ◽  
Author(s):  
C. P. Burmester ◽  
S. Quong ◽  
L. T. Wille ◽  
R. Gronsky ◽  
B. T. Ahn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Contrast Effects ◽  
Oxygen Loss ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Out Of Plane ◽  
Partial States

AbstractHigh resolution electron microscopy is used to investigate the effect of electron irradiation induced oxygen loss on the states of partial order in YBa2Cu3Oz. Contrast effects visible in the [001] zone image as a result of the degree of the out-of-plane correlation of these ordered states are investigated. Using statistical simulations to aid in the analysis of the HREM images, an interpretation based on a kinetically limited evolution of the variation of long range [001] ordering is proposed.

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.

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