Showing papers on "Transmission electron microscopy published in 1989"
TL;DR: The structure and interfacial reaction in sputtered MoSi multilayers have been studied using cross-section transmission electron microscopy, electron diffraction, Rutherford backscattering, and low-angle x-ray diffraction as mentioned in this paper.
Abstract: The structure and interfacial reaction in sputtered Mo‐Si multilayers have been studied using cross‐section transmission electron microscopy, electron diffraction, Rutherford backscattering, and low‐angle x‐ray diffraction. Low‐temperature (T<550 °C) annealing was performed in a rapid‐thermal‐annealing furnace and in situ in the microscope. No solid‐state amorphization was observed, in spite of the presence of amorphous alloy interfacial layers in the as‐deposited structure. Instead, the amorphous interlayers crystallize, and growth of the crystalline product, hexagonal‐MoSi2, proceeds. The bilayer period contracts during the reaction, as the disilicide is more dense than its constituents.
157 citations
TL;DR: A1 (purity, 99·7%) with 0·1 or 2 mm grains was torsionally deformed at 400°C and 0·2s-1 up to equivalent strains of 60 as discussed by the authors.
Abstract: A1 (purity, 99·7%) with 0·1 or 2 mm grains was torsionally deformed at 400°C and 0·2s-1 up to equivalent strains of 60. Tangential sections were examined by polarized light, transmission electron microscopy and scanning electron microscopy. The grains wound into helicoids with an axial thickness varying inversely with the strain. Subgrains persisted at a constant size (about 7 μm) and equiaxed throughout the straining from 0·5 to 60. Relative misorientations, of structural units were determined by scanning transmission electron microscopy channelling patterns, which confirmed the X-ray diffraction textures. The grains, with their boundaries strongly serrated, retained their distinctness up to strains of 10 for 0·1 mm grains and up to 60 for 2 mm grains, while their thickness was greater than the subgrain diameter. For the former at strains of 20-60, the microstructure consists of subgrains having a mixture of small- and large-angle boundaries; this development is called geometric dynamic recrysta...
124 citations
TL;DR: In this paper, a transmission electron microscopy study of porous silicon reveals that pores selectively propagate in the 〈100〉 crystallographic directions on both n and p-type silicon, independent of dopant concentration or anodization conditions.
Abstract: A transmission electron microscopy study of porous silicon reveals that pores selectively propagate in the 〈100〉 crystallographic directions on both n‐ and p‐type silicon, independent of dopant concentration or anodization conditions.
119 citations
TL;DR: In this article, a series of graphitic samples associated with a uranium deposit has been studied by micro-Raman spectrometry, transmission electron microscopy and X-Ray diffraction.
103 citations
TL;DR: In this paper, the surface roughness of TiO2 thin layers has been investigated by electron microscopy by two different and complementary methods: direct imaging and carbon-platinum replica observation.
99 citations
TL;DR: In this article, a method for direct observation of the early stages of growth of superconducting films by transmission electron microscopy (TEM) is reported, which uses well-characterized, single-crystal TEM foils as substrates for the deposition process.
Abstract: A method for the direct observation of the early stages of growth of superconducting films by transmission electron microscopy (TEM) is reported. The technique uses well‐characterized, single‐crystal TEM foils as substrates for the deposition process. Ultrathin films of YBa2Cu3O6+x (YBCO) were prepared by pulsed laser deposition from stoichiometric bulk samples directly onto (001) oriented MgO thin‐foil substrates. Observation of the film by TEM is possible without any post‐deposition specimen preparation. The epitactic nature of the film growth is shown by analysis of the moire fringe pattern and by selected area diffraction. In addition to an interconnected film, copper oxide particles and stoichiometric ablated clusters were observed.
94 citations
TL;DR: In this paper, the authors studied the interface of 10 osseointegrated implants of pure titanium, Tivanium, Vitallium, and stainless steel, and found an unpredictable variation in interface ultrastructure within 500-1,000 nm of the metal surface, common to all the materials.
Abstract: In a material of 10 osseointegrated implants of pure titanium, Tivanium, Vitallium, and stainless steel, 23 interface areas were studied by transmission electron microscopy. The implant site was the upper tibia of mature rabbits, and the observation time was 11 months. The absence of a cellular reaction was verified. However, even in cases of apparently uniform osseointegration, electron microscopy revealed an unpredictable variation in interface ultrastructure within 500-1,000 nm of the metal surface, common to all the materials. There was no structural feature that was specific for a particular material.
92 citations
TL;DR: In this paper, a solution-cast Nafion® membrane by RuO4 vapor was examined by transmission electron microscopy (TEM) and both solution casting and positive staining techniques were employed.
90 citations
TL;DR: In this article, a study of sintered magnets revealed two types of grain boundaries: one containing no intergranular phase between hard magnetic grains and one composed of nonmagnetic Nd-rich phases.
88 citations
TL;DR: In this paper, the growth kinetics of amorphous interlayer (a interlayerbb) in polycrystalline Ti films on singlecrystal silicon has been studied by cross-sectional transmission electron microscopy.
Abstract: The growth kinetics of amorphous interlayer (a interlayerbb) in polycrystalline Ti films on single‐crystal‐silicon has been studied by cross‐sectional transmission electron microscopy. The growth was found to follow a linear growth law initially in samples annealed at 350–425 °C. The activation energy of the linear growth was measured to be 1.6±0.3 eV. Maximum thicknesses of the a interlayers were measured to be of the order of 10 nm. The formation of an a interlayer was observed in samples annealed at a temperature as high as 600 °C. The formation and growth kinetics of a interlayers in Ti/Si and Ni/Zr systems are compared. Essential factors for the formation and growth of an a interlayer are discussed. The results represent the first report on the growth kinetics of an a interlayer in metal thin films on single‐crystal silicon.
84 citations
TL;DR: In this article, the initial growth process of a W rod with a 15nm diameter has been observed in situ by using electron beam induced surface reaction and direct writing onto Si, GaAs, and poly(methylmethacrylate) resist have been demonstrated by electron beam-induced surface reaction using XeF2, Cl2 and ClF3 sources.
Abstract: W deposition, using a WF6 source by electron beam induced surface reaction, has been studied by Auger electron spectroscopy (AES) and transmission electron microscopy (TEM). The initial growth process has been observed in situ by AES and TEM. As a result, it became clear that a growth rate for W is ∼1 A/min at 2×10−7 Torr and β‐W clusters are formed by electron beam irradiation of the WF6 adlayer. Moreover, it has been observed that W layers are formed by coalescing the W clusters by electron beam irradiation at 5×10−7 Torr WF6 gas pressure. Furthermore, a nanostructure involving a W rod with a 15‐nm diameter has been demonstrated by using electron beam induced surface reaction. Direct writing onto Si, GaAs, and poly(methylmethacrylate) (PMMA) resist have been demonstrated by electron beam induced surface reaction using XeF2, Cl2, and ClF3 sources. The electron beam stimulated etched depth is proportional to the electron dose. A 0.5‐μm linewidth Si and PMMA resist patterns have been fabricated at 4×10−3 a...
TL;DR: In this article, microanalytical results (conventional and scanning transmission electron microscopy, energy dispersive x-ray spectroscopy, and electron energy loss spectrography) were obtained on a Σ=25 bicrystal before and after annealing in sealed ampoules at 900°C.
Abstract: Grain boundary (GB) electrical activity is increased by heat treatment in silicon; the origin of the phenomenon is a subject of controversy and is often attributed to oxide precipitation. This letter presents microanalytical results (conventional and scanning transmission electron microscopy, energy dispersive x‐ray spectroscopy, and electron energy loss spectroscopy), obtained on a Σ=25 bicrystal before and after annealing in sealed ampoules at 900 °C. The enhancement of the electrical activity, confirmed by electron beam induced current and deep level transient spectroscopy, is shown to appear at the boundary simultaneously with precipitates containing copper and nickel. The major role of the fast diffusing 3d metals on the GB electrical properties is demonstrated.
TL;DR: Using TEM, Auger spectroscopy, EDX, and convergent beam electron diffraction, a thorough characterization of the interphase region between SCS6 fibers and Ti-6Al-4V matrix in a metal matrix composite has been performed as discussed by the authors.
Abstract: Using TEM, Auger spectroscopy, EDX, and convergent beam electron diffraction, a thorough characterization of the interphase region between SCS6 fibers and Ti–6Al–4V matrix in a metal matrix composite has been performed. The interphase region is shown to be very complex, consisting of numerous layers of varying compositions and thicknesses. The chemical interaction of the fiber and matrix results in a 0.5–1.5 μm thick TiC layer. Evidence for the existence of a Tix Siy (C) layer is also presented. The SCS6 overlayer on the fibers has inhibited any chemical interaction between the matrix and the SiC filament itself, 60% of the interphase region originating from the SCS6 protective coating. In situ fracture experiments (in an Auger spectrometer) reveal that fracture takes place between the TiC and an amorphous carbon layer.
TL;DR: This work has utilized VLM in conjunction with SEM and HVEM to correlate changes in shape and surface structure with changes in the internal structure of platelets, and found it advantageous to use colloidal gold-labeling procedures, because these markers are detectable by all three forms of microscopy.
Abstract: Scanning electron microscopy (SEM), especially low-voltage (1 KeV) high-resolution SEM, can be used in conjunction with stereo pair high-voltage (1 MeV) transmission electron microscopy (HVEM) of whole spread cells or thick sections effectively to correlate surface structure with internal structure. Surface features such as microvilli, pits, pseudopodia, ruffles, attached virus, and other surface-related morphologic characteristics can be identified using SEM, while underlying cytoskeletal structure and organelle organization can be viewed by HVEM of the same preparation. However, the need to "prepare" cells for electron microscopy precludes observation in the living state. The use of several types of video-enhanced light microscopy (VLM) permits observation of living cells such that certain surface and internal features can be observed at a relatively high level of resolution or detection. Thus, changes in living cells can be followed, and at appropriate times the cells may be chemically fixed or rapidly frozen and prepared for ultrastructural examination by electron microscopy. We have utilized VLM in conjunction with SEM and HVEM to correlate changes in shape and surface structure with changes in the internal structure of platelets. In addition, we have found it advantageous to use colloidal gold-labeling procedures, because these markers are detectable by all three forms of microscopy. Using this approach we have labeled platelet membrane GPIIb/IIIa, a receptor for RGD-containing adhesive proteins, with gold-fibrinogen or gold-anti-IIb/IIIa. The initial binding and subsequent movement of gold-fibrinogen-IIb/IIIa complexes in living platelets was followed by VLM. The movement of individual labels could be mapped. Subsequent observation by low-voltage (1 KeV) high-resolution SEM and HVEM permits visualization of the same individual receptors tracked by LM. The final position on the membrane or the position-in-transit when fixative was added was determined relative to surface ultrastructure (SEM) and internal, particularly cytoskeletal, ultrastructure (HVEM).
TL;DR: In this paper, the U4O9 in irradiated fuel was identified by the presence of diffuse extra reflections in electron diffraction and was attributed to rapid penetration of oxygen along grain boundaries coated with closely spaced fission gas microbubbles.
TL;DR: In this paper, Czochralski silicon samples have been heated at 750°C for periods of 48,96 and 431 h under clean conditions appropriate to device fabrication.
Abstract: Czochralski silicon samples have been heated at 750°C for periods of 48,96 and 431 h under clean conditions appropriate to device fabrication. The loss of oxygen from solution was measured from the strength of the 9 pm absorption band with the samples at 4·2 K; detailed information about the SiO2 precipitates was obtained by measurements on many foils using transmission electron microscopy, and by small-angle neutron scattering. The three techniques were applied to common samples. The measurements show excellent overall self-consistency and some new features have been found in the transmission electron microscopy analysis. In general, platelets are observed with length increasing from 12 to 26 nm, and with thicknesses of about 2 nm. The number density of particles drops from 2 × 1013 to 7 × 1012 cm−3 as the heating time is increased. We deduce a value of the oxide density to be 2·6 g cm−3, which is somewhat higher than the normally quoted value of 2·3 g cm−3 for amorphous silica.
TL;DR: The products of the transformation of natural (Mg0.83Fe0.17)2SiO4 olivine have been prepared at various high pressures (between 25 GPa and 90 GPa), and high temperature in a laser-heated diamond-anvil cell (DAC) as mentioned in this paper.
Abstract: The products of the transformation of natural (Mg0.83Fe0.17)2SiO4 olivine have been prepared at various high pressures (between 25 GPa and 90 GPa), and high temperature in a laser-heated diamond-anvil cell (DAC). Studies of the high-pressure phases have been made by transmission electron microscopy (TEM), and X-ray microanalysis.
IBM1
TL;DR: In this article, the microstructure of silicon nitride at temperatures associated with potential high-temperature applications of the material is addressed experimentally by quenching thin (transmission electron microscopy) samples from 1450°C and examining them in the microscope.
Abstract: The outstanding question as to the microstructure of silicon nitride at temperatures associated with potential high-temperature applications of the material is addressed experimentally by quenching thin (transmission electron microscopy) samples from 1450°C and examining them in the microscope. The morphology of the microstructure is qualitatively unchanged compared to the materials slowly cooled, for example, after hot-pressing, to room temperature. The most significant difference is that the thickness of the intergranular phase is larger, typically 2 to 10 nm, as compared to the ∼ 1 nm observed in the hot-pressed material. In addition there is an apparent increase in the volume fraction of the intergranular phase at the three-grain junctions. On the basis of a number of supporting experiments including both hot-stage transmission electron microscopy (up to 1000°C) and Auger electron spectroscopy of material fractured and examined at 850°C, the change in microstructure is concluded to occur at temperatures above about 1000°C.
TL;DR: In this paper, the results of TEM analysis have revealed that the debris of the microstructures is composed of a polymer with a higher density, which is a more stable polymer than polyethylene 2,6naphthalate.
Abstract: KrF excimer laser photoablation of semicrystalline poly(ethylene 2,6‐naphthalate) showed characteristic microstructures on the surface. These stable and well‐defined structures were investigated with scanning electron microscopy, transmission electron microscopy (TEM), and x‐ray photoelectron spectroscopy. The results of TEM analysis have revealed that the debris of the microstructures is composed of a polymer with a higher density.
TL;DR: In this article, the effect of substrate temperature and post-deposition annealing temperature on the structural properties of the SnO 2 films for gas sensor application was studied, and it was observed from X-ray diffraction (XRD) results that the films deposited at lower substrate temperatures are amorphous and become polycrystalline SnO at 350 °C.
AT&T1
TL;DR: In this paper, the authors studied the as-deposited structure and annealing behavior of NiSi 2 on clean Si surfaces and showed the importance of the thickness and orientation dependence to the free energy of very thin films due to the significant fraction of interfacial atoms.
TL;DR: In this article, a single-scattering theory for unfiltered and zero-loss filtered images in the electron spectroscopic imaging mode of a transmission electron microscope is presented. But the analysis is limited to the case of amorphous films.
Abstract: SUMMARY
Measured values of the transmission of amorphous films as a function of the objective aperture and film thickness can be described by a single-scattering theory for unfiltered and zero-loss filtered images in the electron spectroscopic imaging mode of a transmission electron microscope. The theory can be applied to estimate the gain of contrast by zero-loss filtering for specimen structures larger and smaller than the chromatic aberration disc.
TL;DR: In this paper, the atomic structure of the (111) interface between CoSi2 (type A and B) and Si was investigated by high-resolution transmission electron microscopy, combined with image simulations.
Abstract: The atomic structure of the (111) interface between CoSi2 (type A and B) and Si is investigated by high‐resolution transmission electron microscopy, combined with image simulations. Type B interfaces of CoSi2 layers formed by thermal reaction of vapor deposited Co on (111) oriented Si, of Si/CoSi2/Si heterostructures, and of CoSi2 precipitates formed by high‐dose Co implantation were examined. The coordination of the Co atoms at all B‐type interfaces is found to be eightfold, in accordance with theoretical predictions. Type A interfaces of CoSi2 precipitates and continuous CoSi2 layers, formed by ion implantation and subsequent annealing, showed clear evidence for the presence of sevenfold coordinated interfacial Co.
TL;DR: In this paper, a lattice resolution electron microscopy image of a heterogeneous catalyst has been used to study atomic rearrangements in catalysts and catalyst supports under reaction conditions by using an in-situ cell for an electron microscope.
Abstract: A catalyst has been imaged with lattice resolution whilst surrounded by flowing gas, using a specially constructed in-situ cell for an electron microscope. This advancement demonstrates the feasibility of directly studying atomic rearrangements in catalysts and catalyst supports under reaction conditions by electron microscopy. Such studies show promise of providing a detailed understanding of the mechanisms involved in certain types of heterogeneous catalyst.
TL;DR: In this article, the ability to produce transition metal clusters dispersed in a polymeric matrix by metal sputtering and plasma polymerization in a rf capacitively coupled diode reactor was investigated.
Abstract: The ability to produce transition‐metal clusters dispersed in a polymeric matrix by metal sputtering and plasma polymerization in a rf capacitively coupled diode reactor svstem was investigated. An in situ plasma diagnostic technique, i.e., optical emission spectroscopy, was used to predict the metal concentration of the film. Characterization of metal‐containing plasma‐polymerized propane thin films was realized using x‐ray photoelectron spectroscopy, x‐ray fluorescence, Raman spectroscopy, transmission electron microscopy, and electron diffraction. Evidence is given that the metal is present in its metallic state in the organic matrix and in the form of uniformly dispersed small particles. The shape and size of gold and cobalt particles at equivalent volume fractions are shown to be different, which is reflected in different electrical percolation threshold values for the two systems.
TL;DR: In this paper, the authors examined the topographic and internal features of diamond films grown by the hot filament assisted chemical vapor deposition method and discussed the growth mechanisms in terms of growth mechanisms.
Abstract: Scanning and transmission electron microscopy (SEM and TEM) have been used to examine the topographic and internal features of diamond films grown by the hot filament assisted chemical vapor deposition method. Films were grown under conditions chosen to provide three distinctly different diamond microstructures. One of these film structures is virtually free of stacking faults and twins within the grains. This paper relates internal and external growth features to each other, to Raman spectra and to the growth conditions. The growth features are discussed in terms of growth mechanisms.
01 Jan 1989
TL;DR: In this paper, the authors examined the topographic and internal features of diamond films grown by the hot filament assisted chemical vapor deposition method and discussed the growth mechanisms in terms of growth mechanisms.
Abstract: Scanning and transmission electron microscopy (SEM and TEM) have been used to examine the topographic and internal features of diamond films grown by the hot filament assisted chemical vapor deposition method. Films were grown under conditions chosen to provide three distinctly different diamond microstructures. One of these film structures is virtually free of stacking faults and twins within the grains. This paper relates internal and external growth features to each other, to Raman spectra and to the growth conditions. The growth features are discussed in terms of growth mechanisms.
TL;DR: In this paper, the authors used weak beam technique to find dislocations and planar defects in the AIN grains of sintered material using transmission electron microscopy (TEM) as a function of the concentration of sintering additives (Y2O3).
Abstract: Extended defects in the AIN grains of sintered material have been studied by transmission electron microscopy (TEM) as a function of the concentration of sintering additives (Y2O3). Evidence of dislocations and planar defects has been found. Using the weak beam technique, dislocations were found to be dissociated in the basal plane. The deduced reduced stacking fault energy,γ′, has been found to confirm the correlation betweenγ′ and the charge redistribution index in III–V and II–VI compounds. The formation of planar defects during sintering is also discussed.
TL;DR: In this article, a comparative study of separation by implanted oxygen structures using spectroscopic ellipsometry (SE) and transmission electron microscopy is presented, where the strength of SE to measure the layer thicknesses of multilayer structures is illustrated.
Abstract: The first results are presented of a comparative study of separation by implanted oxygen structures using spectroscopic ellipsometry (SE) and transmission electron microscopy. The strength of SE to measure the layer thicknesses of multilayer structures nondestructively is illustrated. Some limitations of the technique are also indicated.