Showing papers on "Electron backscatter diffraction published in 1991"
Book•
01 Apr 1991TL;DR: In this article, the principles of image formation by a lens and the transmission electron microscope are discussed. And the observation of crystal defects and microstructures associated with deformation is discussed.
Abstract: Preface Introduction 1. Principles of image formation by a lens 2. The transmission electron microscope 3. Kinematical theory of electron diffraction 4. Dynamical theory of electron diffraction 5. The observation of crystal defects 6. High-resolution transmission electron microscopy 7. Chemical analysis in the transmission electron microscope 8. Mineralogical applications of TEM - I: defects and microstructures in undeformed specimens 9. Mineralogical applications of TEM - II: dislocations and microstructures associated with deformation References Index.
110 citations
TL;DR: In this paper, a detailed analysis of the crystallographic and magnetic structure of YTiFe 11 N 0.5 is presented, and the relationship of the magnetic properties to the crystal structure is discussed.
77 citations
TL;DR: In this paper, a retarding field analyzer with a micro-channel plate-intensified detector was used to obtain two-dimensional diffraction images of the rutile TiO 2 (110) surface.
74 citations
TL;DR: In this paper, a TEM study of the crystallography and defect structure of the ternary compound semiconductor CuInSe2 has been carried out, where single crystal samples grown by the vertical Bridgman technique and polycrystalline films grown by a magnetron sputtering technique were studied.
Abstract: A TEM study of the crystallography and defect structure of the ternary compound semiconductor CuInSe2 has been carried out. Single crystal samples grown by the vertical Bridgman technique and polycrystalline films grown by a magnetron sputtering technique were studied. A convergent beam diffraction ZAPMAP for CuInSe2 was assembled and indexed which allowed us to perform systematic defect analysis experiments. Selected area diffraction patterns from a number of zone axes have been compared with theoretically calculated patterns and some subtle differences which have been noted have been explained in terms of double diffraction and/or inelastic scattering effects. We have also demonstrated a qualitative method of studying anti-site defect densities in these crystals by studying diffuse diffraction effects and the intensities of weak Bragg reflections in selected area diffraction patterns. Polycrystalline films tend to exhibit planar defects such as microtwins and stacking faults on (112) planes and...
58 citations
TL;DR: In this article, the adsorption site of Ag atoms with respect to the unreconstructed Si crystal was uniquely determined using transmission X-ray diffraction, consistent with one of the two honeycomb-chained triangle models previously proposed by the authors.
49 citations
TL;DR: Aldred et al. as mentioned in this paper obtained energy-filtered convergent-beam electron diffraction (CBED) patterns from a 10A˚region of the specimen in a scanning transmission electron microscope (STEM) equipped with a digital image-acquisition system.
49 citations
TL;DR: In this paper, a single-domain Si(111)4 × 1-In surface has been studied by μ-probe reflection high-energy electron diffraction (RHEED) to elucidate the symmetry of the 4 × 1 surface.
38 citations
TL;DR: In this paper, an electron micrograph of chlorinated copper phthalocyanine at 2 A resolution taken on the Kyoto 500 kV electron microscope has been enhanced to 1 A resolution by incorporating the information from the corresponding electron diffraction pattern.
TL;DR: In this paper, a straightforward kinematic analysis of diffraction from metastable three-dimensional crystallites of Ge grown on Si(001) is presented, and low-energy electron diffraction data from these crystallites agree with diffraction images calculated for a structure determined from scanning tunneling microscopy data.
Abstract: A straightforward kinematic analysis of diffraction from metastable three‐dimensional crystallites of Ge grown on Si(001) is presented. Low‐energy electron diffraction data from these crystallites agree with diffraction images calculated for a structure determined from scanning‐tunneling microscopy data. Additionally, reflection high‐energy electron diffraction images predicted for these crystals agree with existing data.
TL;DR: In this article, the intensity behavior of the specular beam in reflection high energy electron diffraction (RHEED) from GaAs(111)B grown by molecular beam epitaxy (MBE) is investigated for various growth and diffraction conditions.
Abstract: The intensity behavior of the specular beam in reflection high‐energy electron diffraction (RHEED) from GaAs(111)B grown by molecular‐beam epitaxy (MBE) is investigated for various growth and diffraction conditions. The temporal behavior during the initial growth of a buffer layer is examined at a fixed diffraction condition. Intensity increase is observed during and after the initial stages of buffer layer growth and found to saturate after about 80 monolayer growth. Intensity oscillations are seen starting at different moments of initial growth, the earliest observed after only 14 monolayer growth. These results are used to guide and control GaAs(111)B growths with mirrorlike surface morphology.
TL;DR: In this article, the authors describe the characterization of Bi-Sr-Ca-Cu-O superconducting films by X-ray diffraction and demonstrate the change in the relative volume fraction as a function of the etch depth.
Abstract: X-ray diffraction has been used extensively to assess the crystalline phase composition of superconducting ceramics. In instances where randomly oriented powders are available, X-ray diffraction provides a means of identifying not only the phases present but also the volume fraction of each phase. In instances where ultrathin films ( 0.2 μm) the ability to measure phase composition by X-ray diffraction is hampered by the fact that due to the limited effective X-ray penetration depth the X-ray beam may not sample all depths of the film equally. This phenomenon could result in a lessening of the contribution to the final diffraction pattern by phases concentrated near the substrate-film interface. This paper describes the characterization of Bi-Sr-Ca-Cu-O superconducting films by X-ray diffraction. Reactive beam ion etching experiments made it possible to observe the change in the relative volume fraction of three superconducting phases as a function of etch depth.
TL;DR: The microstructural features of the powder C60 material have been studied by using scanning microscopy, electron diffraction, and high resolution electron microscopy as discussed by the authors, which reveals that the grains in the samples are packed by extensively disordered crystallites as well as amorphous granules.
Abstract: The microstructural features of the powder C60 material have been studied by using scanning microscopy, electron diffraction, and high resolution electron microscopy. Scanning electron microscopy observation reveals that the grains in the samples are packed by extensively disordered crystallites as well as amorphous granules. Electron diffraction measurements have identified that the crystals of C60 have two kinds of structure, one is face‐centered‐cubic (fcc) with unit cell parameter a=1.41 nm, and the other has the hexagonal closest packed (hcp) structure with cell parameters a=0.958 nm and c=1.63 nm. High resolution electron microscopy as well as electron diffraction observations clearly show the random crystallites packing in the C60 grains.
TL;DR: The crystal structure of the odd-chain paraffin, n-tritriacontane, nC33H68, is determined directly by using low-dose electron microscope images and electron diffraction intensity data from epitaxially grown microcrystals to calculate an electrostatic potential map.
Abstract: The crystal structure of the odd-chain paraffin, n-tritriacontane, nC33H68, is determined directly by using low-dose electron microscope images and electron diffraction intensity data from epitaxially grown microcrystals. Phases of the most intense "polyethylene" reflections are determined from triplet structure-invariant relationships often used in X-ray crystallography. Low-dose electron microscopic images provide phases of the low-angle "lamellar" reflections and these can be used with one-dimensional structure-invariant relationships to determine other phases on the 00l reciprocal row. The phase set is sufficient to calculate an electrostatic potential map which is directly interpretable as a structure image at atomic resolution.
TL;DR: In this article, the GaMo4S8 transforms at T, = 45(5) K from a cubic high-temperature modification with ordered defect spinel structure (space group F43m, a = 9.7356(2) Ä at 300 K) to a rhombohedrally distorted low temperature modification {R3m, = 6.8506(2), â h = 60.533(1)° at 8 K).
Abstract: GaMo4S8 transforms at T, = 45(5) K from a cubic high-temperature modification with ordered defect spinel structure (space group F43m, a = 9.7356(2) Ä at 300 K) to a rhombohedrally distorted low-temperature modification {R3m, = 6.8506(2) Ä, â h = 60.533(1)° at 8 K). The transition is of first Order, shows a hysteresis of about 4 K, and leaves about 30% of the cubic phase untransformed. Lattice parameters as a function of temperature are reported between 8 K and 300 K, and structure refinements are performed by the Rietveld method from data recorded on a Guinier diffractometer at 8 K and 300 K. The tetrahedral M04 Clusters expand during the phase transjtion at one of their triangular bases, [Mo — MoL = 2.814(3) Ä at r = 3 0 0 K ; 2.89(1) Ä at T=SK, while the other intra-cluster distances, [ M o M o j ] = 2.814(3) Ä at 7 = 300 K; 2.81(2) Ä at r = 8 K, and inter-cluster distances, [M04-M04] = 4.070(3) Ä at 7 = 300 K; 4.02-4.04(2) Ä at r = 8 K, remain approximately constant. ' Permanent address: Institut für Chemische Technologie anorganischer Stoffe, Getreidemarkt 9, Technische Universität, A-1060 Wien, Austria. ^ Permanent address: Universite Cadi Ayyad, Faculte des Sciences, Marrakech, Maroc. 112 M. Frangois et al.
01 Jan 1991
TL;DR: Tong et al. as discussed by the authors presented a new method on lensless electron microscope (LEM) for achieving high resolution and overcoming effects of multiple scattering, which is capable of magnifying individual atoms with ε 0.3 ε ≈ 0.
Abstract: The symposium began with electron diffraction studies of surfaces. Ichimiya applied dynamical studies of reflection high-energy electron diffraction to obtain the structure of absorbed species on Si. He showed that a full dynamical analysis was necessary to understand measurements of RHEED intensity vs. angle and that especially in symmetry directions surface resonances were critical. Yet the analysis is still difficult. Tong presented a new method on lensless electron microscope (LEM) for achieving high resolution and overcoming effects of multiple scattering. The technique is capable of magnifying individual atoms with {ge}0.3 {Angstrom}, unprecedented in electron microscope. These proceedings contain the first published disclosure of the LEM. The technique was demonstrated for B on Si(111) and revealed the structure of two or more atomic layers - something that STM cannot do. Surface ordering and phase transition studies also featured prominently. Hinch showed the sensitivity of atomic beam diffraction - a technique with as much signal as reflection electron diffraction but which sees a very different scattering potential. Mailander et al. showed differences between calculated surface critical exponents and those measured by x-ray diffraction.
TL;DR: In this article, a dynamical theory is proposed starting from the coupled wave equations for describing inelastic electron scattering in perfect crystals and crystals with defects, which can be statistically evaluated before any numerical calculations, essentially providing an easy way for treating coherence, incoherence or partial coherence in dynamical electron diffraction.
TL;DR: In this paper, the diffraction amplitude of a reflection of a strained-layer superlattice is given explicitly in terms of the strains and thicknesses of the super lattice bilayer using the kinematical theory of electron diffraction.
TL;DR: In this article, an electron detection system using linear charge coupled device imagers has been developed, which allows rapid parallel measurement of the diffraction signal in a direct electron counting mode.
Abstract: An electron diffraction apparatus is described that has been designed specifically for use with molecular beams containing small particles in the nanometer size range. A novel electron detection system has been developed, using linear charge coupled device imagers, which allows rapid parallel measurement of the diffraction signal in a direct electron counting mode. The apparatus also features a 100 kV electron gun and electron optics derived from a Philips EM 300 electron microscope. Details of the apparatus are presented and measurement results on small silver particles in a beam of helium carrier gas are also given; these are interpreted using an icosahedral structure for the small particles.
TL;DR: In this article, the side bands due to purely composition and combined composition-strain modulation in plan-view specimens of a nominally Ge 0·5Si0·5(Snm)/Si(25nm) superlattice have been obtained by large-angle convergent-beam electron diffraction.
Abstract: Side bands due to purely composition and combined composition-strain modulation in plan-view specimens of a nominally Ge0·5Si0·5(Snm)/Si(25nm) superlattice have been obtained by large-angle convergent-beam electron diffraction. The intensities of the side bands have been calculated from a periodic tension-compression model of the superlattice bilayer using the kinematical theory of electron diffraction. Accurate values of elastic strains in the bilayer and of the Ge content can be obtained in this way.
Book•
15 Aug 1991
TL;DR: In this article, the interaction of X-Rays and Particle Beams with materials is discussed. But the authors focus on the physical properties of Fourier transform and do not consider the theoretical aspects of the process.
Abstract: PART ONE - INTERACTION OF X-RAYS AND PARTICLE BEAMS WITH MATERIALS: Waves, Particle Beams and Matter Basics on Radiation-Matter Interactions Basic Theory of Elastic Scattering Elastic Scattering by Individual Atoms, Atomic Scattering Amplitude Diffraction by a Crystal Basic Theory of Electron Diffraction Secondary Emission Absorption of Radiations in Materials PART TWO - RADIATION GENERATION AND MEASUREMENT: Sources of X-Rays, Electrons, Thermal Neutrons and Ions Radiation Detectors and Spectrometers PART THREE DIFFRACTION TECHNIQUES APPLIED TO MATERIAL ANALYSIS: X-Ray and Neutron Diffraction Applied to Crystalline Materials Electron Diffraction or Thin Crystalline Layers. PART FOUR - X-RAY, ELECTRON AND SECONDARY ION SPECTROMETRY APPLIED TO MATERIAL ANALYSIS: Elemental Analysis by X-Ray Fluorescence Electron Probe Microanalysis Electron Spectrometry for Surface Analysis X-Ray Absorption Spectrometry and Electron Energy Loss Spectrometry Secondary Ion Mass Spectrometry for Surface Analysis PART FIVE - TECHNIQUES OF ELECTRON MICROSCOPY: Scanning Transmission Electron Microscopy Analytical Electron Microscopy Appendix A: Physical Quantities. Units. Universal Constants. Notations B: Reciprocal Space. Reciprocal Lattice C: Basic Properties of Fourier Transforms D: Spectrometric Tables E: Abbreviations and Acronyms F: Radioprotection.