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Misfit-layered compounds (MLCs) are formed by the combination of different lattices and exhibit intriguing structural and morphological characteristics. MLC SrxLa1-xS-TaS2 nanotubes with varying Sr composition (10, 20, 40, and 60 Sr atom %, corresponding to x = 0.1, 0.2, 0.4 and 0.6, respectively) were prepared in the present study and systematically investigated using a combination of high-resolution electron microscopy and spectroscopy. These studies enable detailed insight into the structural aspects of these phases to be gained at the atomic scale. The addition of Sr had a significant impact on the formation of the nanotubes with higher Sr content, leading to a decrease in the yield of the nanotubes. This trend can be attributed to the reduced charge transfer between the rare earth/S unit (LaxSr1-xS) and the TaS2 layer in the MLC which destabilizes the MLC lattice. The influence of varying the Sr content in the nanotubes was systematically studied using Raman spectroscopy. Density functional theory calculations were carried out to support the experimental observations. © 2019 Serra et al. Center for Nanoscale Science and Technology, CNST: 43535000350000, 720821 Government Council on Grants, Russian Federation: NORTE-45-2015-02 Israel Science Foundation, ISF: 7130970101 We acknowledge the support of the Israel Science Foundation (grant No. 7130970101). We also wish to acknowledge the Perlman Family Foundation, the Kimmel Center for Nanoscale Science Grant No. 43535000350000, and the Irving and Azelle Waltcher Foundations in honor of Prof. M. Levy Grant No. 720821. The activity of A.E. was supported by Act 211 Government of the Russian Federation, contract No.02.A03.21.0006. E.A.A and F.L.D acknowledge the financial support by the N2020: Nanotechnology based functional solutions (NORTE-45-2015-02).

The implantation-induced defects of crystalline silicon implanted with helium ions to a dose of 5 × 1016/cm2 at 600 °C were investigated. The sample was analyzed by transmission electron microscopy and high-resolution electron microscopy. Faceted cavities are observed in the damaged layer. Concurrently the distribution of interstitial-type defect clusters was investigated by conventional electron microscopy in bright and dark field. Many rod-like defects, which belong to {1 1 3}, {1 1 1} and (−2 0 0), are formed in the end of the projected range. In front of the damaged layer, some ribbon-like defects are formed, which belong to 〈2 0 0〉, 〈1 −1 1〉 and 〈1 3 −3〉. The possible reasons of the observed defect clusters are discussed.

This work presents our recent findings that a small addition (0.5 at. %) of Cr to FeCo–2V alloy leads to a great improvement in creep resistance. High resolution electron microscopy was applied to study microstructural evolution of the Cr added alloy during the creep process performed at 600 °C under 200 MPa. At an initial step of the creep, there appear plate-like precipitates with bcc/fcc structure as well as some rod-like ones with hcp structure. A coherent relationship is identified between the precipitates and bcc FeCo matrix. With prolonging the creep, the rod-like hcp precipitates are revealed to remain in the bcc matrix, showing a good stability under the creep condition and in turn resulting in piling-up of dislocations to a great extent around the precipitates. In addition, the Cr added alloy is shown to have a large stress exponent of 8.4, indicating a strong interaction between dislocations and the hcp precipitates.

As reported in our previous works, a Mg-7Gd-5Y-1Nd-0.5Zr alloy recently developed exhibited remarkable age-hardening responses and excellent mechanical properties at both room and elevated temperatures. In Mg-7Gd-5Y-1Nd-0.5Zr alloy, the β precipitate phase was assumed to be one of the main strengthening phases in peak-aged samples. This study aimed to determine the crystal structure and orientation relationship of the β precipitate phase in Mg-7Gd-5Y-1Nd-0.5Zr alloy using transmission electron microscopy and high-resolution electron microscopy. The results indicated that the β precipitate had a face-centered cubic structure with a lattice parameter of a=2.22 nm. The orientation relationship between the β precipitate phase and the α-Mg matrix was ( 1 ¯ 12 ) β / / ( 1 ¯ 100 ) α , [ 110 ] β / [ 0001 ] α . The β plates formed on prismatic planes could play an important role in alloy strengthening by proving effective barriers to gliding dislocations. A single β plate often contained several domains of ( 1 1 ¯ 1 ) β twin-related variants. A composition of Mg5(Y0.4Gd0.4Nd0.2) was suggested for the β phase in Mg-7Gd-5Y-1Nd-0.5Zr alloy.

Twin boundary (TB) and twinning dislocations (TDs) in { 10 1 ¯ 1 } twins in deformed polycrystalline cobalt (Co) were studied by high-resolution electron microscopy. The { 10 1 ¯ 1 } TB tends to be flat and a mirror plane. The observed TD was characterized directly from the experimental image by the circuit-mapping method and predicted by the topological model. The observed TD with a localized core can stably exist in { 10 1 ¯ 1 } twins in Co.

Carbon extracted from a cathodic graphite rod following arc-discharge in helium is examined using high-resolution electron microscopy. It is found that, in addition to the well known extended graphitic tubules ('buckytubes'), carbon produced in this way contains many other novel graphitic structures. Of particular interest are small hollow particles which, although essentially tubular, appear to differ in significant ways from the extended tubules. Evidence for tetrahedral bonding in some of the graphitic particles is also presented.

High-resolution electron microscopy is used to study the structure of two typical non-graphitizing carbons before and after heat treatment at temperatures in the range 2100–2600°C. It is found that these heat treatments can result in the formation of closed carbon nanoparticles, which are apparently fullerene-like in structure. This suggests that fullerene-like elements were present in the original carbons and leads us to propose a new model for the structure of non-graphitizing carbons.

High-resolution electron microscopy was applied to analyze the continuous precipitated particles of the γ-Mg 17 Al 12 phase with Pitsch-Schrader OR in the heat-treated AZ91 alloy at 473 K for 8 h. The existence of a continuous precipitated particle with the Pitsch-Schrader OR including the selection of the habit plane and the growth direction in Mg–Al system is rationalized by the constrained coincidence site lattice/constrained complete pattern shift lattice (CCSL/CDSCL) model and the O-lattice theory.

Polycrystalline Sr3CaMn2CoO9 and (Sr0.5Ca0.5)15Mn7Co4O33 have been synthesized and characterised by X-ray and electron diffraction, high resolution electron microscopy and magnetic measurements. These oxides constitute the α = 3, β = 1 and α = 4, β = 1 terms of the homologous series (A3B2O6)α(A3B3O9)β, respectively. Isolated rows of polyhedra sharing faces along the c-axis are made up of units of two and one face-sharing octahedra (occupied by Mn) linked by one trigonal prism (occupied by Co) in an ordered way. The chains are separated by columns of Sr/Ca atoms. Magnetic measurements suggest antiferromagnetic correlations in the two new commensurate monodimensional oxides. The influence of the size of alkaline-earth atoms on the long-range magnetic interactions is discussed.

In the present work, transmission electron microscopy (TEM) techniques were used in order to study the morphology and investigate the structural properties of a (BixSb1-x)2Te3(BST) thin film. The sample was fabricated on silicon substrate by pulsed laser deposition (PLD) method. Towards this aim, cross sectional and planar view samples were prepared, suitable for High Resolution Electron Microscopy. Results revealed a polycrystalline, c-axis oriented film with coherent boundaries between neighboring columnar grains. © Springer International Publishing Switzerland 2015. 164 3 7 3-7

High-resolution electron microscopy is employed to observe the atomic arrangement of very tip of the growing martensite plate and that of the growing bainite. Transition lattice region with a certain dimension (more than a few nm), of which the structure is neither fcc nor bcc, but an intermediate one between fcc and bcc lattice, is found in martensite but not in bainite. Because of this fact, it is concluded that the martensitic transformation is of the shear-type transformation and the bainitic transformation is of the diffusion-type transformation.

Correlative microscopy combines the advantages of both light and electron microscopy to enable imaging of rare and transient events at high resolution. Performing correlative microscopy in complex and bulky samples such as an entire living organism is a time-consuming and error-prone task. Here, we investigate correlative methods that rely on the use of artificial and endogenous structural features of the sample as reference points for correlating intravital fluorescence microscopy and electron microscopy. To investigate tumor cell behavior in vivo with ultrastructural accuracy, a reliable approach is needed to retrieve single tumor cells imaged deep within the tissue. For this purpose, fluorescently labeled tumor cells were subcutaneously injected into a mouse ear and imaged using two-photon-excitation microscopy. Using near-infrared branding, the position of the imaged area within the sample was labeled at the skin level, allowing for its precise recollection. Following sample preparation for electron microscopy, concerted usage of the artificial branding and anatomical landmarks enables targeting and approaching the cells of interest while serial sectioning through the specimen. We describe here three procedures showing how three-dimensional (3D) mapping of structural features in the tissue can be exploited to accurately correlate between the two imaging modalities, without having to rely on the use of artificially introduced markers of the region of interest. The methods employed here facilitate the link between intravital and nanoscale imaging of invasive tumor cells, enabling correlating function to structure in the study of tumor invasion and metastasis.

The infinite layer compound Ca0.85Sr0.15CuO 2 has been synthesized by the sol-gel technique using the acetate gel route. The compound is found to be single-phasic as evidenced from the powder X-ray and electron diffraction measurements. EDAX analysis confirms the presence of homogenous stoichiometric phase pertaining to the composition Ca 0.85Sr0.15CuO2. High-resolution electron microscopy (HREM) studies reveal interesting defects in the infinite layer frame work of the system. Apart from the usual strain and shear induced defects observed in the lattice, which is common among the perovskite compounds, the main finding is the defect along [0 1 0], occurring due to the intercalation of extra AO layer in the CuO2 plane. Such a defect is accommodated in the lattice by the increase in the interplanar distance (which is basically the c-axis parameter) from 3.2 to 3.4 � in the defective layer. This implies the formation of square pyramidal oxygen co-ordination of copper at the defect site. ? 2005 Elsevier Ltd. All rights reserved.

An YNi2B2C thin film grown on a MgO(001) substrate by pulsed laser deposition has been investigated by transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). Plan-vi...

Boron nitride (BN) nanohorns with various tip angles were synthesized by an arc-melting method, and atomic structure models for BN nanohorns were proposed from high-resolution electron microscopy. Stability and electronic structures of the BN nanohorns were investigated by molecular orbital/mechanics calculations, which indicated that multi-walled BN nanohorns would be stabilized by stacking of BN nanohorns. The energy gaps of the BN nanohorns were calculated to be 0.20∼0.85 eV, which are lower compared to those of BN clusters and nanotubes.

Electron diffraction and high resolution electron microscopy have been used to characterize two new one-dimensional superstructures in the A Rh O system (A = Ca, Sr) related to the 2H-ABO3-type. They are formed by the intergrowth of n A3A′BO6 blocks, showing the Sr4RhO6-type, with A12A′2B8O30 blocks, constituted by two A3O9 and two A3A′O6 layers alternating in the stacking sequence 1:1, leading to the A27A′7B13O60 ( n = 5 ) and A30A′8B14O66 ( n = 6 ) compositions. A crystallographic shear mechanism is proposed to describe the structural relationship between Sr4RhO6 (A3A′BO6-type) and the new superstructures.

The core structures of perfect 60 and edge dislocations in diamond are investigated atomistically in a density-functional based tight-binding approach, and their dissociation is discussed both in terms of structure and energy. Furthermore, high resolution electron microscopy is performed on dislocation cores in high-temperature, high-pressure annealed natural brown diamond, and HRTEM image simulation allows a comparison of theoretically predicted and experimentally observed structures.

High-resolution electron microscopy is used to study interfaces between solids with varying degree of atomic ordering. Applying a recently developed technique the structure of amorphous germanium near (111) oriented crystalline silicon is described by its two-dimensional distribution function ρ(x,y) of atoms, and properties of ρ(x,y) are extracted from experimental images. Using extensive image simulations it is further shown that the technique is suitable to measure composition profiles at coherent heterointerfaces.

The structures and components of different pigments from the Feng Hui tomb situated in Bin County, Shaanxi Province, dated in the Five Dynasties (907–960 AD), were analyzed by Raman spectroscopy and high-resolution electron microscopy (HREM). It is shown that the red, yellow and black samples are cinnabar, PbSO4–PbO and carbon black, respectively, and well preserved, which provide scientific data for later conservation. Moreover, the results indicate that HREM and Raman analysis are very effective for identifying ancient inorganic pigments at low concentrations. Copyright © 2004 John Wiley & Sons, Ltd.

Growth of Ni on (001) Au has been widely studied. Furthermore it has been shown that a structural change occurs when an Au/Ni multilayer is heated up. This transformation can be described as an ordering which is unexpected from the equilibrium phase diagram. A high-resolution electron microscopy study of the transformation of a coherent Au/Ni multilayer is presented in this paper. The transformation has been characterized by in-situ HREM and by extensive image processings made on both simulated and experimental images.

High-resolution electron microscopy, mass spectrometry and molecular mechanics/orbital calculations of the boron nitride-based clusters showed the formation of B 36 N 36 and Y@B 36 N 36 . Image simulations of these clusters confirmed the proposed structure model.

The contact resistance of Au/Ni/p-GaN ohmic contacts for different annealing conditions was measured. This was then correlated with microstructure, including phase distribution, observed by high-resolution electron microscopy combined with energy-filtering imaging. A contact resistance of 2.22 x 10(-4) ohms cm2 for Au/Ni contacts to p-GaN after annealing at 500 degrees C for 5 min in air ambient was obtained. NiO layers were identified at the interface and upper area of annealed Ni/Au/p-GaN for air ambient. In addition, an Au layer was found at the interface of p-GaN due to a reversal reaction during annealing. Identification of the observed phases is discussed, along with possible formation mechanisms for the ohmic contacts in the Au/Ni/p-GaN system.

Crystal structures of a homologous series of Co-based layered cuprates, CoSr2(Y,Ce)sCu2O5+2s (s=1–3), have been investigated by high-resolution electron microscopy (HREM) and electron diffraction (ED) techniques. For all the three phases ED patterns showed double periodicity along a direction parallel to the CoO layers, indicating a regular alternation of two types of CoO4-tetrahedra chains within the layers. Also seen was ordering of the chains along the layer-stacking direction for the s=1 phase (Co-1212); ED patterns simulated based on the proposed superstructure model well reproduced the observed patterns. For the s=2 (Co-1222) and s=3 (Co-1232) phases in which an additional fluorite-type layer-block is inserted between two CuO2 planes, HREM and ED analysis revealed complete disorder of the CoO4 chains along the layer-stacking direction. This implies that the interlayer ordering is mainly controlled by the distance between the neighboring CoO layers.

A quantitative method is described for the measurememnt of displacements and strains by high-resolution electron microscopy. The image is considered to be composed of periodic sets characterized by Fourier analysis. The local amplitude and geometric phase of lattice fringes can be determined in this way. The analysis of the phase distribution leads to the determination of the local lattice configuration. The method is illustrated by different examples and its application conditions are discussed.

Atomic structures of surface and interface in (Hg,Tl,Pb)-based superconductors were investigated by high-resolution electron microscopy. The interfaces observed in Tl-based superconductors have the disordered region with ∼1 nm thickness, which would be suitable for barrier layers for tunneling junctions. Although the {001} planes of (Hg,Tl)-based oxides are fairly stable, most of the {100} planes are unstable, and atomic rearrangement was often observed. However, the HREM image of Hg 0.5 Tl 0.5 Ba 2 CuO 5 {100} showed the stable Ba–O–Ba layer at the surface, and oxygen atom positions were determined. The present study indicates that the surfaces of the Hg- and Tl-based superconductors are strongly dependent on the crystallographic planes and crystal structures.

High-resolution electron microscopy is discussed as a measuring, rather than an imaging, technique. It is shown that the interpretation or the images could greatly benefit from a quantitative instead of a qualitative approach accompanied by quantitative statistical experimental design.

Twinning plays an important role in phase transformations and can have significant effects on microstructural evolution. Different roles of twinning in the development of microstructures during precipitation and phase transformations are reviewed and illustrated with examples from investigations by high-resolution electron microscopy, including the effect of multiple twinning on the development of Ge precipitates in Al-Ge and Ag-Ge alloys, the twin dissociation of grain boundaries in Au, the formation of hexagonal Si at twin intersections and the effect of twin boundaries on the equilibrium shape of Pb inclusions in Al.

An Al–Ni–Ru decagonal quasicrystal with 0.4 nm periodicity, which has a good long-range basic quasiperiodic order, was observed to form in rapidly solidified Al–Ni–Ru alloys. Its structure has been studied by means of high-resolution electron microscopy and high-angle annular detector dark-field techniques, and compared with that of a superlattice Al–Ni–Ru decagonal quasicrystal formed by conventional solidification. The results reveal that the rapidly solidified Al–Ni–Ru decagonal quasicrystal with 0.4 nm periodicity has a new basic structural state which is characterized by a mixture of 2 nm atomic columnar clusters with and without pentagonal symmetry.

Pd 80 Pt 20 and Pd 85 Pt 15 alloys were exposed at 673 K to a hydrogen pressure of 100 MPa for 4 h, which is called hydrogen heat treatment (HHT). After HHT the pressure composition isotherms at 273 K change remarkably and H-diffusion is enhanced. The change can be interpreted by a decomposition into a continuous Pd-rich and an embedded Pt-rich alloy. Direct evidence for this hypothesis is provided for the first time from high resolution electron microscopy. It will be shown that coherent platelets are formed after HHT which are two atomic layers thick and have an average diameter of ∼10 nm. Simulating the contrast observed in the electron microscope shows that the plates are Pt-rich.

High-resolution electron microscopy (HREM) was used to obtain information about structural variations in poly[1,6-di(N-carbazolyl)-2,4-hexadiyne) (polyDCHD) nanocrystals. Several particles in different crystallographic zones were imaged with high spatial resolution of up to 0.19nm, resulting in image information on a subunit-cell level (a = 1.74nm, b = 1.29nm and c = 0.49nm; β = 108.3°, P21/a; Z = 2). The average nanocrystal had a nominally rectangular shape and a size of about 40 nm × 80 nm with the major growth direction along the polymer chains (001). Most of the HREM images correspond to the [100] or [120] zone. In a few cases, it was also possible to image crystals oriented in the [001] zone with the polymer chain axis normal to the carbon substrate. Image interpretation was done by comparison with multislice HREM image simulations based on an approximation for the crystal structure and imaging conditions. These simulations performed for polyDCHD indicate that the HREM image is sensitive to ...

The structure of grain boundaries in rocks, which are composed mainly of fine-grained quartz and feldspar, was studied by high-resolution electron microscopy (HREM) . At most of the boundaries, not only between the same minerals but also between different minerals, lattice fringes in connected grains meet each other at interfaces with no other appreciable phases. In these boundaries, it has been found that some of the straight segments of the boundaries correspond to a low-index plane of one of the connected grains. Boundaries containing voids, with a spheroidal shape elongated along the boundaries, were observed. It is suggested that these boundaries were formed by healing of microcracks.

As shown in Chap. 5, metakaolinite shows amorphous to words X-ray and spinel too is a very weakly crystalline material. In view of it, an extremely powerful technique high resolution electron microscopy is applied for characterization.

Two new decagonal quasi-crystals (D-phases), which have periods of 0.4 and 1.6 nm, respectively, have been found to form with different compositions in conventionally solidified Al–Ni–Ru alloys. The diffraction patterns of these two D-phases display a large number of sharp diffraction spots located at exact tenfold symmetry positions and almost no diffuse streaks, indicating that they are highly ordered quasi-crystals. The D-phase with 0.4-nm periodicity exhibits a pronounced S1-type superlattice order. The D-phase with 1.6-nm periodicity can be formed as a major phase by annealing at around 900°C. By means of high-resolution electron microscopy, the structural characteristics of the D-phase with 1.6-nm periodicity have been revealed.

Atomic displacements and interface reconstructions near a La0.9Sr0.1MnO3‐SrTiO3 interface are studied by use of the focal reconstruction technique applied in high-resolution electron microscopy. By using a quantitative model, column positions are determined with high precision (better than 0.004 nm) by least-squares minimization. A displacement vector map and interatomic distances are calculated. From these a structure model for the interface is proposed. The interface has a facetted shape, where the interatomic distance is modulated. Possible local oxygen deficiency in SrTiO3 near the interface has been observed. q 2000 Elsevier Science Ltd. All rights reserved.

Single decagonal quasicrystals of Al 70 Ni 15 Co 15 were grown by the Czochralski method at Ar atmosphere. The grown crystals were of single decagonal phase without any secondary phases due to the peritectic reaction and contained a large single quasicrystal of cm order size. The high quality and single quasicrystallinity of them were examined by the Laue transmission photography, single crystal X-ray diffraction, and high-resolution electron microscopy investigations.

The possibility of direct detection of doping atoms in the B12 cluster solid by high-resolution electron microscopy (HREM) was investigated by using calculated residual indices and difference images. The HREM images of B12-based rhombohedral boron doped with (Al, Cu) and carbon atoms were calculated at the Scherzer defocus. The difference images of Al2.6Cu1.8B105/B12 and B13C2/B12 showed Al, Cu and C atomic positions clearly at crystal thickness of 3.1 nm. Crystallographic image processing was applied to the experimental image of Al2.6Cu1.8B105, which provided the average Al and Cu atom positions. In addition, HREM images recorded from thin regions (

Keywords: Bones ; electron diffraction ; high-resolution electron microscopy ; hydroxyapatite ; image processing ; image simulation ; micro- and nanoparticles Reference CIME-ARTICLE-1999-026doi:10.1046/j.1365-2818.1999.00608.x Record created on 2007-02-15, modified on 2017-05-12

The structure of grain boundaries in a granite-origin ultramylonite, composed mainly of fine-grained feldspar and quartz, was studied by high-resolution electron microscopy (HREM). At most of the boundaries, not only between the same minerals but also between different minerals, lattice fringes in adjacent grains meet at the interface with no other appreciable phases. In these boundaries, some of the straight segments correspond to a low-index plane of one of the connected grains. Boundaries containing voids, with a spheroidal shape elongated along the boundaries, were observed only between quartz grains. It is suggested that these boundaries were formed by healing of microcracks. The structural width of major boundaries, deduced from lattice-fringe imaging, is less than about 0.5 nm.

The n integer members of the A n +2 B n B ′O 3 n +3 homologous series keeping B = B ′=Co the same have been characterized by selected area electron diffraction and high resolution electron microscopy. Its commensurate modulated structure is made up of chains, separated by A atoms, running along the c direction containing a succession of one Co atom ( B ′) in prismatic trigonal sites and n Co atoms octahedrally coordinated sharing faces. All of them can be described as ordered intergrowths of two structures of the end members of the family, 2H–BaCoO 3 ( n =∞) and Ca 3 Co 2 O 6 ( n =1). The modulation observed in all terms can be described as a function of the difference between the c -axis of the Co sublattice with respect to the 2H structure. Members of the series can be obtained by modifying the distance between layers keeping B =Co the same, as shown in (Sr 1− x Ba x ) 6 Co 5 O 15 ( n =4), Sr 5 Co 4 O 12 ( n =3), and (Sr 0.5 Ca 0.5 ) 4 Co 3 O 9 ( n =2).

Disordering of both yttrium and boron atoms in YB56 was observed, in three dimensions, from difference images of high-resolution electron microscopy (HREM) and simulated images from an X-ray determined structural model. Averaged HREM images recorded using a slow-scan charge-coupled device camera from thin regions (less than 5 nm) along the [100], [110] and [111] directions of the YB56 were compared with calculated images based on the X-ray data. A residual index R HREM was used for image analysis to determine the crystal thickness and defocus value of the observed images. Based on the experimental conditions which minimized the R HREM values, difference images between observed and simulated images were calculated. These difference images observed along the three directions of the YB56 showed the atomic disorder, which are yttrium positions and boron clusters around the yttrium atoms. This approach is useful for the evaluation of disordered atomic positions in the crystal.

As one of our systematic studies of the modulated structures of a series of new homologous compounds RM O 3 (ZnO) m ( R =Sc, In, Y, and La; M =In, Fe Ga, and Al; m =integer), this paper reports the modulated structure of Fe 2 O 3 (ZnO) 15 ( R =Fe; M =Fe) studied by high-resolution electron microscopy. It is found that the main and satellite spots in the diffraction patterns can be indexed as h a * + k b * + l c * + m q by considering a monoclinic unit cell of a =0.57 nm, b =0.33 nm, c =4.5 nm, and β =92° and a modulation wave vector of q=b * /34.8+c * /2. The possible space groups for the basic structure are C 2, Cm , and C 2/ m , and the possible four-dimensional superspace groups for the modulated structure are C C 2 1 , C Cm 1 , and C C 2/ m 1 1 . The crystal structure of Fe 2 O 3 (ZnO) 15 consists of Fe–O layers interleaved with 16 Fe/Zn–O layers. In the high-resolution image, the modulated structure appeared as zigzag-shaped contrasts among the Fe/Zn–O layers, where Fe is in high concentration. Compared with those of In M O 3 (ZnO) m ( R =In; M =In, Fe and Ga) reported in our earlier paper, the special features of the present modulated structure are the half-periodicity relative shift of the neighboring zigzag-shaped contrasts and the appearance of modulation within the Fe–O layers.

Environmental electron microscopy has become an important scientific method for fundamental studies of dynamic chemical reaction processes in heterogeneous catalysis and of catalytic growth of carbon nanotubes. Outstanding contributions are resulting from the ability to observe gas‐catalyst surface reactions in situ, on the atomic scale. A great deal of structural and chemical information including lattice modification of working catalysts is possible. This is key to understanding novel reaction processes, including release mechanism of structural oxygen in oxide catalysts in selective oxidation of hydrocarbons and to designing improved catalysts. This brief survey of the recent spectacular developments in environmental high resolution electron microscopy shows that new opportunities are being opened up in catalysis.

This tutorial paper is the mannscript of a lecture given in the Harnack-Haus in Berlin during the antumn school 1998 on Metal Clusters. The aim of this lecture was to give some hints for quantitative electron microscopy. The interpretation of electron microscopic images depends on the mode of contrast. In particular the phase contrast is described and how it affects the images.

Further high-resolution electron microscopy studies have been performed on coherent thin non-equilibrium precipitates and unique nanocrystals with an identical orientation, which are produced from sputter-deposited amorphous Ti-48.2 at.° Ni thin films by heat treatments near or below the crystallization temperature Tc . Abundant evidence is provided for the previously proposed mechanisms for formation of the subnanometric precipitates near Tc and the nanocrystals below Tc ; it is as follows. For heat treatment below Tc , firstly a thin plate precipitate with the {100} habit plane, which has a bct lattice with its tetragonal axis perpendicular to the habit plane, is frequently observed at the crystal-amorphous interface, secondly the bct precipitates constituting the boundaries between nanocrystals are arranged in such a way that they can truncate an approximately spherical nanocrystal, while keeping the coherency with the B2 matrix at the {100} habit plane, thirdly enrichment of Ti atoms is detec...

Zeolites are one of the most important materials currently used in the petroleum industry for a wide variety of catalytic transformations. However, they are increasingly being considered for other applications such as for designing quantum-confined materials in their spaces. With such applications in mind, precise characterisation of zeolites and related porous materials has never been more necessary. Here we show how electron diffraction coupled with high-resolution imaging can reveal the detailed fine structure in both the bulk and at the surface of these materials. A variety of case studies are considered which include ETS-10, FAU, LTL and FSM-16.

Surface structures of the (Hg,T1)-based superconducting and related oxides were studied by high-resolution electron microscopy. The {100} planes of the 1201-type structure were found to be stable, and Hg0.5Tl0.5Ba2CuO5 showed a preferred atomic surface consisting of Ba layers. The {001} planes were also stable in HgTlBa2CuOx and TlBa2CaCu2O7. The present work indicates that the stable {100} planes of (Hg,Tl)-based superconducting oxides would be suitable for future device applications.

The exact three-dimensional structure of a nanosized colloidal particle of Pd3 P was determined directly from high-resolution transmission electron microscopy (HRTEM) images that were recorded in several crystallographic directions. An HRTEM image recorded along [011] is shown on the right. The cores of the particles were excluded from the analysis because of severe multiple diffraction.

Glomerulocyte cellulosic bundles of Polyzoa vesiculiphora were investigated by microdiffraction and high-resolution electron microscopy. In each bundle, hundreds of cellulose microfibrils, having a rectangular cross-sectional shape, are packed regularly with their 0.6 nm lattice planes parallel to each other. Lattice images reveal that the 0.6 nm plane is parallel to the longer edge of the cross section which is similar to the lattice organization of cellulose with a squarish cross section in Valonia spp. More interestingly, all the microfibrils in a bundle have the same directionality of crystallographic c-axis, which suggests that the biosynthesis of the microfibrils within particular bundle occurs unidirectionally.

Submicrometer-grained (SMG) structures were produced in Cu and Ni using an intense plastic straining technique, and the grain boundaries and their vicinities were observed by high-resolution electron microscopy. The grain boundaries exhibited zigzag configurations with irregular arrangements of facets and steps, and thus they were found to be in a high-energy nonequilibrium state. A similar conclusion was reached earlier for SMG Al–Mg solid solution alloys which have much lower melting points than Cu and Ni, suggesting that nonequilibrium grain boundaries are a typical feature of metals processed by intense plastic straining.