Effect of a surface layer on the investigation of AuFe alloys by transmission electron microscopy

1991 ◽  
Vol 26 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Chen-Chia Chou ◽  
Haydn Chen ◽  
C.M. Wayman
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Layer ◽  
Transmission Electron ◽  
Fe Alloys

Direct UHV-TEM Observation of Palladium Clusters on a Silicon Surface

2004 ◽  
Vol 10 (1) ◽  
pp. 134-138 ◽  
Author(s):  
Masaki Takeguchi ◽  
Kazutaka Mitsuishi ◽  
Miyoko Tanaka ◽  
Kazuo Furuya
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Layer ◽  
Silicon Surface ◽  
Lattice Structure ◽  
Plan View ◽  
Palladium Clusters ◽  
Transmission Electron ◽  
Pd Clusters

About 1 monolayer of palladium was deposited onto a silicon (111) 7 × 7 surface at a temperature of about 550 K inside an ultrahigh vacuum transmission electron microscope, resulting in formation of Pd2Si nanoislands and a 1 × 1 surface layer. Pd clusters created from an excess of Pd atoms on the 1 × 1 surface layer were directly observed byin situplan view high-resolution transmission electron microscopy. When an objective aperture was introduced so that electron diffractions less than 0.20 nm were filtered out, the lattice structure of the 1 × 1 surface with 0.33 nm spacing and the Pd clusters with a trimer shape were visualized. It was found that image contrast of the 1 × 1 lattice on the specific height terraces disappeared, and thereby an atomic structure of the Pd clusters was clearly observed. The appearance and disappearance of the 1 × 1 lattice was explained by the effect of the kinematical diffraction. It was identified that a Pd cluster was composed of three Pd atoms without a centered Si atom, which is consistent with the model proposed previously. The feature of the Pd clusters stuck at the surface step was also described.

Electron Microscope Investigation of PVD Coated Aluminium Alloy Surface Layer

2012 ◽  
Vol 186 ◽  
pp. 192-197 ◽  
Author(s):  
Tomasz Tański ◽  
Krzysztof Labisz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Layer ◽  
Electron Microscope ◽  
Aluminium Alloy ◽  
Aluminium Alloys ◽  
Wear Resistant ◽  
Electron Microscope Investigation ◽  
Microscope Investigation ◽  
Transmission Electron

The purpose of this work is electron microscope investigation of the Ti/TiCN/TiAlN and Cr/CrN/CrN coatings deposited by PVD process. The investigations were performed using scanning and transmission electron microscopy for the microstructure determination. By mind of the transmission electron microscopy the high resolution and phase determination was possible to obtain. The morphology was studied as well the lattice parameters for the layer matrix and substrate phase identification using diffraction methods was applied. After the coating of the aluminium alloys AlSi9Cu and AlSi9Cu4 with the selected coatings there are crystallites detected with the size of several tenth of diameter. The investigated samples were examined metallographically using electron microscope with different image techniques, also EDS microanalysis and electron diffraction was made. As an implication for the practice a new layer sequence can be possible to develop, based on PVD technique. Some other investigation should be performed in the future, but the knowledge found in this research shows an interesting investigation direction. The originality and value of this combination of TEM investigation for PVD deposited surface lasers on aluminium alloys makes the investigation very attractive for automotive and other industry branches. Some practical implications and employment of the surface treatment technology for elements, made from tool materials, with the PVD and CVD methods, to obtain the high wear resistant coatings, makes it possible to improve the properties of these materials by – among others – decreasing for example their friction coefficient, microhardness increase, improvement of the tribological contact conditions in practical use. One original value is it also to applied the PVD method on a common material like aluminium alloy. The double layer coatings worked out In the PVD process on the Al0Si-Cu alloys substrate hale the following configuration of the layers: bottom layer/gradient layer/wear resistant hard surface layer.

The distribution of condensed defect structures formed in annealed boron-implanted silicon

1969 ◽  
Vol 311 (1504) ◽  
pp. 75-78 ◽  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Layer ◽  
Electron Beam ◽  
Electron Microscope ◽  
Turbulent Jet ◽  
Doping Profile ◽  
Defect Structures ◽  
Transmission Electron ◽  
Boron Ions

Silicon has been implanted with between 10 14 and 10 16 boron ions/cm 2 at energies of 25, 50, 75 and 100 keV; it has also been annealed at temperatures of between 873 and 1073 °K when the implanted boron ions occupy substitutional sites and form a ‘doped’ surface layer in which the doping profile can be accurately controlled, a desirable property in the manufacture of solid state circuits and devices (Large & Bicknell 1967). The implanted layers have been examined by both electron microscopy and electron diffraction before, during and after annealing to study the changes in crystal structures involved. For transmission electron microscope studies the silicon must be thinned to provide areas less than 1 p m in thickness, otherwise the electron beam is entirely absorbed within the specimen. It has been found that a modified form of jet etching using a turbulent jet enables large areas suitable for transmission electron microscopy to be easily produced from all types of specimens, both annealed and unannealed. Although specimens have been prepared and implanted with boron ions of different energies and doses the results discussed, which are typical of the range covered, are those obtained from silicon implanted with single energy 50 keV boron ions with a dose of 2 x 10 15 ions/cm 2 .

Relaxed Si1−xGex Layers on Simox Avoiding a Lattice Mismatched Heterointerface

1992 ◽  
Vol 263 ◽  
Author(s):  
B. Holländer ◽  
S. Mantl ◽  
R. Butz ◽  
W. Michelsen ◽  
Ch. Dieker
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Layer ◽  
Rapid Thermal Annealing ◽  
Alternative Methods ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Yield Values ◽  
First Time ◽  
Minimum Yield

ABSTRACTFor the first time, Si1 xGex layers on amorphous SiO 2 were produced by modification of the Si surface layer of a SIMOX wafer. We used two alternative methods. An additional Si1.. Gey layer was deposited epitaxially on a SIMOX wafer followed by rapid thermal annealing. Diffusional intermixing of the layers produced a homogeneous Si1 xGex layer on SiO 2. In a second attempt, Ge was implanted into the Si surface layer and thermally treated. In both cases epitaxial Si1 xGex layers on SiO2 with minimum yield values around 9% were obtained. Rutherford backscattering and cross sectional transmission electron microscopy were used to characterize the new structures.

scholarly journals Grain refinement at the nanoscale via mechanical twinning and dislocation interaction in a nickel-based alloy

2004 ◽  
Vol 19 (6) ◽  
pp. 1623-1629 ◽  
Author(s):  
N.R. Tao ◽  
X.L. Wu ◽  
M.L. Sui ◽  
J. Lu ◽  
K. Lu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Layer ◽  
Grain Refinement ◽  
Mechanical Twinning ◽  
Surface Mechanical Attrition Treatment ◽  
Dislocation Interaction ◽  
Inconel 600 ◽  
Transmission Electron ◽  
Refinement Mechanism

A nanostructured surface layer was formed on an Inconel 600 plate by subjecting it to surface mechanical attrition treatment at room temperature. Transmission electron microscopy and high-resolution transmission electron microscopy of the treated surface layer were carried out to reveal the underlying grain refinement mechanism. Experimental observations showed that the strain-induced nanocrystallization in the current sample occurred via formation of mechanical microtwins and subsequent interaction of the microtwins with dislocations in the surface layer. The development of high-density dislocation arrays inside the twin-matrix lamellae provides precursors for grain boundaries that subdivide the nanometer-thick lamellae into equiaxed, nanometer-sized grains with random orientations.

Radiation enhanced precipitation and dissolution of precipitates investigated by transmission electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 406-407
Author(s):  
W. Kesternich
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Black Spot ◽  
Large Family ◽  
Dislocation Loops ◽  
Transmission Electron ◽  
Fe Alloys ◽  
Phase Instabilities ◽  
Imaging Conditions

Ni-Cr-Fe alloys are the basis for a large family of super alloys and structural steels to be applied in fast breeder and fusion reactor components. A program has been started in Jülich to investigate the point defect kinetics and irradiation induced phase instabilities in pure Ni-Cr-Fe alloys. Fig. 1 shows the change of electrical resistivity as a function of annealing temperature of a homogenized unirradiated Ni75-Cr13-Fe alloy and of the same alloy after electron irradiation and after α-irradiation. The increase of the resistivity and its subsquent decrease is explained by clustering of atoms and subsequent precipitation.Effects of clustering in the unirradiated and electron irradiated specimens cannot be detected by transmission electron microscopy. Aging at 500 and 600°C for 250 hours also does not reveal any microstructural changes by TEM. After °-irradiation, however, precipitates as well as dislocation loops show up as black spot or black-white contrast depending on the imaging conditions Fig. 2

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