Showing papers on "Transmission electron microscopy published in 1987"
TL;DR: In this paper, a 30-s thermal annealing of sputtered Ti-Si multilayers was studied by cross-section and through-foil transmission electron microscopy, glancingangle Rutherford backscattering, and x-ray diffraction.
Abstract: Reactions upon rapid thermal annealing of sputtered Ti‐Si multilayers have been studied by cross‐section and through‐foil transmission electron microscopy, glancing‐angle Rutherford backscattering, and x‐ray diffraction. The compositions of the samples are 40 at. % Ti, 60 at. % Si and 60 at. % Ti, 40 at. % Si, and the bilayer periodicity is about 10 nm. The silicon layers in the as‐deposited films are amorphous; the titanium layers are polycrystalline hcp. After a 30‐s anneal at 455 °C, significant interdiffusion occurs and we observed the formation of an amorphous Ti‐Si alloy by interfacial reaction. The metastable disilicide, C49 TiSi2, nucleated along with a small amount of TiSi in the sample with higher silicon content (60%) upon annealing at 550 °C for 10 s, but the amorphous alloy remained as the only product of reaction in the 40‐at. % Si sample.
229 citations
TL;DR: In this article, post growth thermal annealing has been used to reduce the defect density of GaAs layers grown on Si substrates by molecular beam epitaxy, and transmission electron microscopy indicates a 100× reduction of the true defect density.
Abstract: Post growth thermal annealing has been used to reduce the defect density of GaAs layers grown on Si substrates by molecular beam epitaxy. Transmission electron microscopy indicates a 100× reduction of the true defect density. Twins and stacking faults were eliminated entirely. Most misfit dislocations were confined within the first ∼150 A GaAs layer and formed a regular and narrow network along the Si/GaAs interface. Similar results were obtained from an ion implanted and annealed specimen.
226 citations
TL;DR: In this paper, the formation of a cryptocrystalline carbon (graphite) reaction-layer interface between the fibres and the matrix was found to be a primary role in the ability to control the chemical reaction which creates the graphitic interface, which was used to comment upon a possible mechanism for the high-temperature embrittlement behavior noted for these materials when they undergo rupture in an aerobic environment.
Abstract: Silicon carbide continuous fibre-reinforced glass and glass-ceramic matrix composites showing high strength and fracture toughness have been studied using thin-foil transmission electron microscopy and scanning transmission electron microscopy (AEM). The outstanding mechanical behaviour of these materials is directly correlated with the formation of a cryptocrystalline carbon (graphite) reaction-layer interface between the fibres and the matrix. A solid-state reaction involving relatively rapid diffusion of silicon and oxygen from fibre to matrix correlates well with the experimental observations. Silica activity in the glass-ceramic matrix is suggested to play a primary role in the ability to control the chemical reaction which creates the graphitic interface. AEM results are used to comment upon a possible mechanism for the high-temperature embrittlement behaviour noted for these materials when they undergo rupture in an aerobic environment.
213 citations
TL;DR: In this article, a multilayered structure containing thin (1-12 nm) layers of W or Mo, alternating with C or Si, has been prepared to produce thin cross-sectional specimens, and direct structural information on the atomic scale has been obtained using an ultrahigh resolution electron microscope.
Abstract: Multilayered structures containing thin (1–12 nm) layers of W or Mo, alternating with C or Si, have been prepared to produce thin cross‐sectional specimens, and direct structural information on the atomic scale has been obtained using an ultrahigh resolution electron microscope. Layer thickness and flatness have been analyzed—the average layer thickness varies by up to 0.6 nm from the average value, and the flatness of the layers depends on the quality of the substrate surface. The degree of crystallinity and crystal orientation within the layers has also been examined. This information should enable more accurate theoretical models to be proposed for the multilayer materials and their x‐ray optical properties. The results for the Mo/Si multilayers suggest a model for their growth when prepared by sputtering.
194 citations
TL;DR: In this article, a cross-sectional transmission electron microscopy was used to explore the uniformity at the metal/GaAs interface and the thermal stability of the AuNiGe contact after the ohmic contact formation.
Abstract: As part of the investigation of the use of AuNiGe as the ohmic contact to n‐type GaAs at a high integration level, cross‐sectional transmission electron microscopy was used to explore the uniformity at the metal/GaAs interface and the thermal stability of the AuNiGe contact after the ohmic contact formation. A close relation between spread of the contact resistance and nonuniformity of the interfacial microstructure of the contact was found. Deposition of 5‐nm‐thick Ni as the first layer of the AuNiGe ohmic contact significantly reduced the spread of the contact resistance and led to the formation of a uniform interface without large protrusions. The improvement in uniformity of compound distribution and the reduction of interface roughness are believed to be due to a change in the sequence of alloying reactions, compared to those in the contact without a Ni first layer. This suggests an ideal interface structure for a low resistance AuNiGe ohmic contact after alloying to be a uniform two layer structure: a high density of the NiAs(Ge) grains contacting the GaAs substrate, and a homogeneous β‐AuGa phase close to the top surface. However, due to the existence of β‐AuGa phases with a low melting point of around 375 °C, the thermal stability of the contact at 400 °C is of serious concern. Segregation of the NiAs(Ge) grains was observed after annealing at 400 °C for 10 h, which reduced the contact areas between the NiAs(Ge) grains and GaAs. During subsequent annealing at this temperature for up to 90 h, liquidlike flow of the β‐AuGa phase was observed which deteriorated the interface uniformity, causing an increase in contact resistance. A typical contact edge slide distance after contact alloying at 440 °C for 2 min was measured to be 0.2 μm and the longest distance among specimens examined was 0.47 μm. This edge deterioration could limit the use of the AuNiGe contact in GaAs submicron devices.
183 citations
TL;DR: A general method has been developed to make the smallest gold-conjugated antibody label yet developed for electron microscopy, which should have wide application in domainal mapping of single molecules or in pinpointing specific molecules, sites, or sequences in supramolecular complexes.
Abstract: A general method has been developed to make the smallest gold-conjugated antibody label yet developed for electron microscopy. It should have wide application in domainal mapping of single molecules or in pinpointing specific molecules, sites, or sequences in supramolecular complexes. It permits electron microscopic visualization of single antigen-binding antibody fragments (Fab') by covalently linking an 11-atom gold cluster to a specific residue on each Fab' such that the antigenic specificity and capacity are preserved. The distance of the gold cluster from the antigen is a maximum of 5.0 nanometers when the undecagold-Fab' probe is used as an immunolabel.
167 citations
TL;DR: In this paper, the first preparation of in situ boron-doped epilayers by a low-temperature chemical vapor deposition process (T=550 °C) was reported.
Abstract: We report the first preparation of in situ boron‐doped epilayers by a low‐temperature chemical vapor deposition process (T=550 °C). Boron incorporation is approximately linear in source gas concentration, and active levels of boron incorporation exceeding 1×1020 B/cm3 have been achieved in as‐deposited 550 °C epilayers. This value exceeds solid solubility limits for boron in silicon at these temperatures by two orders of magnitude, and highlights the nonequilibrium nature of this process. High resolution transmission electron microscopy lattice imaging of this material shows it to be free of boron precipitates, while both plane view transmission electron microscopy and x‐ray topography fail to reveal extended defects. Utilizing low‐temperature processing throughout, p/n junctions have been fabricated in several of the in situ doped layers, with essentially ideal junction quality factors (n=1.0 –1.05) found for junctions of 1×106 μm2.
167 citations
149 citations
TL;DR: In this article, it was shown by means of electron microscopy and electron diffraction that the structural vacancies in Ba 2 YCu 3 O 7−δ undergo an order-disorder transformation accompanied by a change in symmetry from orthorhombic to tetragonal.
139 citations
TL;DR: In this article, the formation of these domains from independent nucleation on a stepped substrate surface is discussed, and a model is presented which discusses how these boundaries separate domains that are in an antiphase relationship to each other.
Abstract: When the surface of β‐SiC, grown epitaxially on (001) silicon by chemical vapor deposition, is chemically etched, boundaries appear which may be observed by optical or scanning electron microscopy. Examination by plan‐view and cross‐sectional transmission electron microscopy shows boundaries in the film which exhibit line or fringe contrast. Convergent beam electron diffraction has been used to show that these boundaries separate domains that are in an antiphase relationship to each other. A model is presented which discusses the formation of these domains from independent nucleation on a stepped substrate surface.
120 citations
TL;DR: Freeze fracture transmission electron microscopy confirmed that Frankia produces vesicles with outer walls thickened by multiple lipid-like monolayers, in proportion to ambient pO(2).
Abstract: When Frankia HFPCcI3 was grown in culture at oxygen O2 levels ranging from 2 to 70 kilopascals O2, under nitrogen fixing conditions, nitrogenase activity adapted to ambient pO2 and showed a marked optimum close to growth pO2. Vesicles were thin walled at low pO2 and very thick walled at high pO2. Freeze fracture transmission electron microscopy confirmed that Frankia produces vesicles with outer walls thickened by multiple lipid-like monolayers, in proportion to ambient pO2.
TL;DR: In this paper, high-resolution electron microscopy observation and electron diffraction analysis of both the (110) and the (10) cross-section specimens strongly suggest that ordering of column III atoms on only two sets of the (111) planes with doubling in periodicity of ( 111) layers is occurring in the crystal.
Abstract: InGaP crystals grown on (001)GaAs substrates by metalorganic chemical vapor deposition are structurally evaluated by transmission electron microscopy. High-resolution electron microscopy observation and electron diffraction analysis of both the (110) and the (10) cross-section specimens strongly suggest that ordering of column III atoms on only two sets of the (111) planes with doubling in periodicity of (111) layers, i.e., In/Ga/In/Ga/In/Ga. . ., is occurring in the crystal. The ordering of the crystal is not perfect, and the ordered regions are assumed to be plate-like microdomains.
TL;DR: In this paper, the microstructure of ion-implanted thin films of the superconductor YBa2Cu3Ox has been investigated by transmission electron microscopy and it was shown that the superconducting properties of the films were dominated by large pancake-shaped grains with their c axis perpendicular to the substrate, forming spherulites, while the interior of the grains showed no irradiationinduced microstructural features until they became amorphous at a dose of 3×1014 ions/cm2.
Abstract: The microstructure of ion‐implanted thin films of the superconductor YBa2Cu3Ox has been investigated by transmission electron microscopy. The superconducting properties of the films were dominated by large pancake‐shaped grains of YBa2Cu3Ox with their c axis perpendicular to the substrate. Other grains of YBa2Cu3Ox whose c axis was parallel to the substrate formed spherulites. Irradiation with 500 keV O+ ions caused amorphous zones to appear on the grain boundaries between the pancake grains, which initially were free of amorphous or second phases. At higher dose a continuous amorphous layer 150 A thick was formed. However, the interior of the grains showed no irradiation‐induced microstructural features until they became amorphous at a dose of 3×1014 ions/cm2. The appearance of the amorphous layer on the grain boundaries at low doses accounts for the reduction in the superconducting transition temperature observed in these films.
TL;DR: In this paper, the authors examined the segregated microstructure in a sputtered Co−18.1 at% Cr film and revealed a definite striped pattern in each crystallite where the stripes run almost perpendicular to grain boundaries.
Abstract: The segregated microstructure in a sputtered Co‐18.1 at. % Cr film is examined. Thin foil samples are prepared for transmission electron microscopy using selective wet etching and ion‐beam milling. The microstructure revealed by selective wet etching shows a definite striped pattern in each crystallite where the stripes run almost perpendicular to grain boundaries. Results of compositional analysis by an energy dispersive x‐ray microanalyzer reveal that these stripes are caused by dissolution of the Co‐rich ferromagnetic regions and that the remaining regions are Cr‐rich and nonmagnetic. The results are explained by a new model for segregated microstructure formation. Ferromagnetic Co‐rich regions are formed coherently in each single‐phase hcp crystallite, with a wall‐like structure perpendicular to the substrate plane. The observed microstructure suggests the existence of a magnetic unit far smaller than the crystallite diameter, which offers superior properties for high‐density perpendicular magnetic recording.
TL;DR: In this paper, a sheet of donor atoms is incorporated in (100) Si during molecular beam epitaxial growth, and the width of such δ−function doping layers is only a few lattice planes.
Abstract: We present a procedure whereby a sheet of donor atoms is incorporated in (100) Si during molecular beam epitaxial growth. Analysis by secondary ion mass spectroscopy and transmission electron microscopy shows that the width of such δ‐function doping layers is only a few lattice planes. Tunneling spectroscopy and transport measurements give evidence for quantum confinement of the electronic charge in the layer and thus confirm the narrow width.
TL;DR: St stereological analyses of the fiber‐tendon junctions of 30‐month‐old mice indicate that, in aging animals, the interfacial ratio is significantly reduced, consistent with the notion that the amount of surface area specialized for force transmission is related to the contractile speed of the fibers.
Abstract: Transmission of contractile tension from skeletal muscle fibers to connective tissue elements is thought to occur at the muscle-tendon junctions, specialized regions at the extreme ends of the fibers. Previous stereological studies on adult mouse and chicken fibers have shown that, with reference to equal cross-sectional areas of myofibrils, the muscle-tendon junctions of faster fibers have significantly more surface membrane devoted to force transmission than do those of slower fibers (Trotter et al.: Anat. Rec. 213:16-25, 1985a; Trotter et al.: Anat. Rec. 213:26-32,1985b; Trotter and Baca: Anat. Rec. 218:256-266, 1987). In the present study we have analyzed the muscle-tendon junctions of 30-month-old mice, employing techniques for scanning and transmission electron microscopy and for ultrastructural stereology which are identical to those previously used to study the same muscles in 4-month-old mice. Whereas the principal structural features of the muscle-tendon junctions of fibers from adult and aged mice are indistinguishable, stereological analyses of the fiber-tendon interfaces indicate that, in aging animals, the interfacial ratio (the ratio of the surface area of force-transmitting membrane to the cross-sectional area of force-generating myofibrils) is significantly reduced. While the interfacial ratio of fast-twitch fibers of the adult plantaris is about 14.5, the corresponding ratio in aged animals is about ten. In the predominantly slow-twitch fibers of the adult soleus, the interfacial ratio is about ten at the insertion and about 12.7 at the origin, whereas the corresponding ratios in the aged animals are both about ten.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: In this paper, the growth features of particulate crystals (e.g., dendrites, whiskers, needles) were identified, and also interpreted in terms of the twin plane reentrant edge (TPRE) mechanism.
Abstract: The films of were prepared from the methyltrichlorosilane (MTS) by low pressure chemical vapor deposition onto the graphite substrates. The results revealed that the growth rate of increased with the MTS flux; besides, the growth rate increased to a maximum and then decreased with increasing deposition temperature. The preferred orientation of the films was examined by x‐ray diffraction, and was found to exhibit a (220) texture in the films of high growth rate and/or long deposition time. The structural morphology was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Observed features indicated the twin plane reentrant edge (TPRE) mechanism as responsible for the growth. The growth features of particulate crystals (e.g., dendrites, whiskers, needles) were identified, and also could be interpreted in terms of the TPRE mechanism.
TL;DR: In this paper, thin LiNbO3 films were prepared from polymerized sol-gel precursor solutions having various concentrations and water:alkoxide ratios in an effort to investigate the effects of these and other processing variables on the resultant film properties and microstructure.
Abstract: Thin LiNbO3 films were prepared from polymerized sol-gel precursor solutions having various concentrations and water:alkoxide ratios in an effort to investigate the effects of these and other processing variables on the resultant film properties and microstructure. Films deposted on silicon substrates were mostly amorphous when pyrolyzed at 435°C for 30 min. Randomly oriented polycrystalline films having distinctive microstnietures were produced using longer heating times or higher temperatures. All of the films exhibited low refractive indices due to porosity, which was attributed to the low level of hydrolysis water required to produce stable polymeric precursor solutions. When single-crystal LiNbO4 was used as the substrate, epitaxial growth of the film resulted. This ideal case establishes the feasibility of producing epitaxial films via sol-gel processing. All films were characterized by transmission electron microscopy (TEM) and thin-film x-ray diffraction patterns.
TL;DR: In this article, the dependence of the structure of indium oxide films on the substrate temperature and on the film thickness was studied using transmission electron microscopy and electron diffraction, and the thermal transformation of the amorphous films after deposition was also studied.
TL;DR: In this article, cubic BN thin films are formed in RF discharge in B2H6 and N2 at low pressures under a magnetic field to confine the plasma, for negatively self-biased substrate electrodes.
Abstract: Cubic BN thin films are formed in RF discharge in B2H6 and N2 at low pressures under a magnetic field to confine the plasma, for negatively self-biased substrate electrodes. Ion bombardment on the growing surface is suggested to play an important role in the formation of cubic BN. The deposited films are characterized by infrared absorption spectroscopy and transmission electron microscopy which show that they are composed of microcrystals of cubic BN with 100-200 A grain size.
TL;DR: The growth of CoSi2 has been studied by deposition and reaction of Co on clean Si surfaces in situ in a modified ultrahigh vacuum transmission electron microscope as mentioned in this paper, where strong interaction between Si and Co occurs yielding an epitaxial film which is believed to be a hexagonally distorted form of the Co2Si structure.
Abstract: The growth of CoSi2 has been studied by deposition and reaction of Co on clean Si (111) surfaces in situ in a modified ultrahigh vacuum transmission electron microscope. On deposition of nominally 20 A Co at room temperature, strong interaction between Si and Co occurs yielding an epitaxial film which is believed to be a hexagonally distorted form of the Co2Si structure. On heating to ∼350 °C the growth of epitaxial CoSi is observed, which transforms to CoSi2 at ∼450 °C. Silicon‐rich phases propagate by lateral motion of phase boundaries. Substantial pinhole density arises in films only after annealing at higher temperatures. The B orientation dominates under similar annealing conditions. In contrast to NiSi2, the growth of cobalt silicide films on Si is dominated by bulk phase formation, with interfacial energy minimized in all cases by epitaxy.
TL;DR: In this article, phase formation in the CoGaAs system is examined in detail and contrasted with other metal-GaAs and metal-silicon systems, and the limitations of each are discussed.
Abstract: The reactions of metals with GaAs are substantially more complex than comparable metal‐silicon systems. In this paper, phase formation in the Co‐GaAs system is examined in detail and contrasted with other metal‐GaAs and metal‐silicon systems. Both elemental and microstructural characterization techniques are used, and the limitations of each are discussed. Cobalt begins to react with GaAs at 375 °C and initially forms a ternary phase of approximate composition, Co2GaAs. Subsequent reactions or higher‐temperature annealing results in the formation of binary phases CoGa and CoAs. The observed phase formation is controlled by the species with the largest diffusion coefficient, and this species is determined by the temperature. At sufficiently high annealing temperatures, arsenic is lost from the surface, and an epitaxial CoGa phase is formed on the GaAs.
Book•
01 Jan 1987
TL;DR: In this article, the theoretical foundation of diffraction contrast in the electron microscope for lattice defect imaging and its computer simulation is discussed. And a survey of preparation techniques for electron microscopy is presented.
Abstract: 1. Methods of Investigation in Electron Microscopy. Conventional electron microscopy: fundamentals of electron optics and instrumentation (H. Bethge, J. Heydenreich). Conventional electron microscopy: image formation (J. Heydenreich, W. Neumann). Electron diffraction: fundamentals and application (W. Neumann, K. Scheerschmidt). High-resolution electron microscopy (W. Neumann, R. Hillebrand, P. Werner). High-voltage electron microscopy (G. Kastner). Scanning electron microscopy: electron-optical and technical fundamentals of the instrument (H. Johansen, U. Werner). Scanning electron microscopy: physical foundations of contrast formation (U. Werner, H. Johansen). Indirect imaging of surfaces by replica and decoration techniques (H. Bethge, M. Krohn, H. Stenzel). Special methods for direct imaging of surfaces: emission electron microscopy, reflection electron microscopy and mirror electron microscopy (H. Bethge, J. Heydenreich). Analytical electron microscopy: combined imaging, diffraction and spectroscopical methods (W. Rechner, R. Schneider). Image processing in electron microscopy (W. Neumann, R. Hillebrand, T. Krajewski). 2. Applications in Solid State Physics. Lattice defect imaging by diffraction contrast (K. Scheerschmidt, R. Gleichmann). Basic processes of plastic deformation (U. Messerschmidt, F. Appel). Microprocesses of fracture (V. Schmidt). Fractography with the SEM (failure analysis) (M. Moser). Morphology of polymers (G.H. Michler). Defects in semiconductors and devices (R. Gleichmann, H. Blumtritt, P. Werner). Molecular processes in crystal growth (K.W. Keller, H. Hoche). Growth and structure of thin films (M. Klaua). Dislocation arrangements in grain boundaries and interphase boundaries (R. Scholz, J. Woltersdorf). The domain structure of ferroelectric and ferromagnetic solids (D. Hesse, K.-P. Meyer). Appendices: The theoretical foundation of diffraction contrast in the electron microscope for lattice defect imaging and its computer simulation (K. Scheerschmidt). Transmission electron microscopy: a survey of preparation techniques (H. Bartsch). Subject Index.
TL;DR: In this paper, computer image simulation was used to assess the effects of damage on high-resolution electron microscope (HREM) images of Y zeolites, which revealed that only for a specimen 10-20 nm thick would the HREM image be a structure image at Scherzer defocus (−60 nm); at thickness greater than 20 nm the images contain non-structural detail due to second-order interferences.
TL;DR: Tin oxide films were prepared by electron beam evaporation of pellets of Specpure SnO2 in the presence of added oxygen as mentioned in this paper, and by optimizing the deposition conditions, transparent and conducting tin oxide films exhibiting the structural characteristics of a predominant SnO 2 phase were produced.
ENEA1
TL;DR: Electron-beam irradiation is shown to induce room-temperature polycrystalline nucleation in the amorphous layer and such a process becomes competitive with solid-phase epitaxy for a dose higher than 5\ifmmode\times\texttimes\fi{}${10}^{5}$ C/${\mathrm{cm}}^{2}$.
Abstract: The technique of cross-sectional electron microscopy has been used to investigate the mechanism of electron-beam-induced solid-phase epitaxy of amorphous silicon at room temperature. Cross sections of samples with surface and buried amorphous layers were irradiated in a transmission electron microscope with electrons of energies higher than the threshold energy for atomic displacement and the induced recrystallization process was characterized. Evidence is given that the dominant mechanism of recrystallization is the diffusion to the amorphous-crystalline interface of the defects produced by elastic displacements both in the crystalline and in the amorphous region. The diffusion length of such defects results in the order of 25--30 nm and is approximatively the same in the crystalline and amorphous Si. Electron-beam irradiation is shown to induce room-temperature polycrystalline nucleation in the amorphous layer. Such a process becomes competitive with solid-phase epitaxy for a dose higher than 5\ifmmode\times\else\texttimes\fi{}${10}^{5}$ C/${\mathrm{cm}}^{2}$.
TL;DR: In this paper, triple crystal diffraction curves are obtained from each sample with the parallel (n, n, n) configuration by measuring the internsity of the main peak as a function of the angular position of the specimen.
Abstract: Interstitial perfect dislocation loops are generated in silicon by high dose silicon ion implantation and furnace annealing in the range 700 to 1000 °C. Triple crystal diffraction curves are obtained from each sample with the parallel (n,–n, n) configuration by measuring the internsity of the main peak as a function of the angular position of the specimen. This procedure allows to make the contribution of Huang diffuse scattering given by the loops to the dynamically diffracted intensity negligible and the sensitivity to lattice distortion higher than in double crystal diffraction case. The truple crystal diffraction curves are simlutatd by computer through application of the dynamical theory of diffraction frojm imperfect crystals. The depth profiles of lattice strain and static atomic disorder are determined. A simple model is used relating these two parameters to the mean radius and surface concentration of the loops. Tthe temperature evolution of size and density of these defects is therefore obtained and compared with the one directly derved by transmission electron microscopy images. The good agreement shown by this comparison ndicates the validity of the model applied and the effectiveness of triple crystal diffraction in the analysis of defects producing Huang scattering.
Perfekte interstitielle Versetzungsloops werden in Silizium durch Hochdosisimplantation von Silizium und Ofentemperung im Bereich von 700 bis 1000 °C erzeugt. Drei-Kristall-Beugungs kurven werden von jeder Probe mit paraller(n,–n, n)-Konfiguration durch Messen der Intensitat des Hauptmaximums in Abhangigkeit von der Winkelposition der Probe erhalten. Dieses Verfahren erlaubt, den Beitrah der diffusen Hung-Streuung zur dynsmisch gestreuten Intensitat der Loops verachlassigbar und die Empfindlichkeit gegenuber Vitterverzerrungen hoher als bei Doppel-Kristallbeugung zu machen. Die Drei-Kristallbeugungskurven werden mittels Computer durch die Anwendung der dynamischen Theorie der Beugung von imperfekten Kristallen simulliert. Die Tiefenprofile der Gitterspannung und der statischen atomaren Fehlordnung werden bestimmt. Ein einfaches Modell wird benutzt, das diese beiden Parameter mit dem mittleren Rakius und der Flachenkonzentration der Loops verknupft. Die Tempeaturentwicklung der Grose und Dichte dieser Defekte wird so erhalten und mit den direkt aus Elektronentransmissionsmikroskopabbildungen a bageleiteten verglichen. Die bei diesem Vergleich erhaltene gute ubereinstimung zeigt die Zuverlassigkeit des benutzten Modells und die Effektivitat der Dreikristallbeungung bei der Analyse der Defekte, die starke Huangstreuung hervorrufen.
TL;DR: In this article, the coexistence of the tenfold twins and decagonal quasicrystal is confirmed by high-resolution electron microscopy, and the development of the 10fold diffraction pattern from the twins is clearly shown, and compared to the ten-fold pattern of the decagonal phase found in the same specimen.
Abstract: Al13 Fe4 tenfold twins, found in rapidly cooled Al–Fe alloys, have been studied by transmission electron microscopy. The development of the tenfold diffraction pattern from the twins is clearly shown, and compared to the tenfold pattern of the decagonal phase found in the same specimen. The coexistence of the tenfold twins and decagonal quasicrystal is confirmed by high-resolution electron microscopy.
TL;DR: In this paper, a commercial lithium aluminosilicate glass-ceramic material is investigated by high-resolution transmission electron microscopy after different heat treatments and evidence is presented that epitaxy of β-quartz crystals on ZrTiO4-type crystallites is the critical step initiating silicate crystallization.
Abstract: A commercial lithium aluminosilicate glass-ceramic material is investigated by high-resolution transmission electron microscopy after different heat treatments. Evidence is presented that epitaxy of β-quartz crystals on ZrTiO4-type crystallites is the critical step initiating silicate crystallization.
TL;DR: Transmission-electron microscopy of the high-superconductivity-transition-temperature oxide Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub x/ reveals the presence of planar defects that persisted on cooling down to the transition temperature, but disappeared on heating above 400 /sup 0/C in in situ experiments inside the electron microscope.
Abstract: Transmission-electron microscopy of the high-superconductivity-transition-temperature oxide Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub x/ reveals the presence of planar defects along the (110) direction more-or-less uniformly spaced (spacing-300 A) and dispersed throughout the specimens. These defects persisted on cooling down to the transition temperature (93 K), but disappeared on heating above 400 /sup 0/C in in situ experiments inside the electron microscope. The possible role of these ''domains'' or interfaces in superconductivity is discussed. The spacing of these interfaces is predicted to be given by ab/(a-b) in rough accord with experimental observation.