scholarly journals FEI Titan G2 80-200 CREWLEY

2016 ◽  
Vol 2 ◽  
Author(s):  
András Kovács ◽  
Roland Schierholz ◽  
Karsten Tillmann
Keyword(s):  
Dark Field ◽  
Electron Gun ◽  
Atomic Scale ◽  
Fourth Generation ◽  
High Brightness ◽  
Transmission Electron ◽  
Wide Range ◽  
Schottky Type ◽  
Technical Specifications ◽  
Electron Energy Loss

<p>The FEI Titan G2 80-200 CREWLEY is a fourth generation transmission electron microscope which has been specifically designed for the investigation of a wide range of solid state phenomena taking place on the atomic scale of both the structure and chemical composition. For these purposes, the FEI Titan G2 80-200 CREWLEY is equipped with a Schottky type high-brightness electron gun (FEI X-FEG), a Cs probe corrector (CEOS DCOR), an in-column Super-X energy dispersive X-ray spectros-copy (EDX) unit (ChemiSTEM technology), a post-column energy filter system (Gatan Enfinium ER 977) with dual electron energy-loss spectroscopy (EELS) option allowing a simultaneous read-out of EDX and EELS signals at a speed of 1000 spectra per second. For data recording the microscope is equipped with an angular dark-field (ADF) scanning TEM (STEM) detector (Fischione Model 3000), on-axis triple BF, DF1, DF2 detectors, on-axis BF/DF Gatan detectors as well as a 4 megapixel CCD system (Gatan UltraScan 1000 XP-P). Typical examples of use and technical specifications for the instrument are given below.</p>

scholarly journals FEI Titan G3 50-300 PICO

2015 ◽  
Vol 1 ◽  
Author(s):  
Karsten Tillmann ◽  
Juri Barthel ◽  
Lothar Houben
Keyword(s):  
Electron Gun ◽  
Atomic Scale ◽  
Fourth Generation ◽  
High Brightness ◽  
Transmission Electron ◽  
Wide Range ◽  
Schottky Type ◽  
Resolution Analysis ◽  
Technical Specifications ◽  
Electron Microscopes

The FEI Titan G3 50-300 PICO is a unique fourth generation transmission electron microscope which has been specifically designed for the investigation of a wide range of solid state phenomena taking place on the atomic scale and thus necessitating true atomic resolution analysis capabilities. For these purposes, the FEI Titan G3 50-300 PICO is equipped with a Schottky type high-brightness electron gun (FEI X-FEG), a monochromator unit, and a Cs probe corrector (CEOS DCOR), a Cs-Cc achro-aplanat image corrector (CEOS CCOR+), a double biprism, a post-column energy filter system (Gatan Quantum 966 ERS) as well as a 16 megapixel CCD system (Gatan UltraScan 4000 UHS). Characterised by a TEM and STEM resolution well below 50 pm at 200 kV, the instrument is one of the few chromatically-corrected high resolution transmission electron microscopes in the world. Typical examples of use and technical specifications for the instrument are given below.

scholarly journals FEI Titan G2 60-300 HOLO

2016 ◽  
Vol 2 ◽  
Author(s):  
Chris Boothroyd ◽  
András Kovács ◽  
Karsten Tillmann
Keyword(s):  
Electron Gun ◽  
Fourth Generation ◽  
Objective Lens ◽  
Electron Holography ◽  
Pole Piece ◽  
High Brightness ◽  
Transmission Electron ◽  
Schottky Type ◽  
Technical Specifications

The FEI Titan G2 60-300 HOLO is a unique fourth generation transmission electron microscope, which has been specifically designed for the investigation of electromagnetic fields of materials using off-axis electron holography. It has a Lorentz lens to allow magnetic field free imaging plus two electron biprisms, which in combination enable more uniform holographic fringes to be used. The instrument also has an ultra-wide objective lens pole piece gap which is ideal for <em>in situ</em> experiments. For these purposes, the FEI Titan G2 60-300 HOLO is equipped with a Schottky type high-brightness electron gun (FEI X-FEG), an image C<sub>s</sub> corrector (CEOS), a post-column energy filter system (Gatan Tridiem 865 ER) as well as a 4 megapixel CCD system (Gatan UltraScan 1000 XP). Typical examples of use and technical specifications for the instrument are given below.

Interlayer mixing in GaAs/AlxGa1-xAs heterostructures as a result of Se+ ion implantation

1988 ◽  
Vol 46 ◽  
pp. 908-909
Author(s):  
E.G. Bithell ◽  
W.M. Stobbs
Keyword(s):  
Ion Implantation ◽  
Diffusion Coefficients ◽  
Dark Field ◽  
Atomic Mass ◽  
Composition Profile ◽  
Semiconductor Heterostructures ◽  
Transmission Electron ◽  
Microscope Images ◽  
Damage Process ◽  
Electron Energy Loss

It is well known that the microstructural consequences of the ion implantation of semiconductor heterostructures can be severe: amorphisation of the damaged region is possible, and layer intermixing can result both from the original damage process and from the enhancement of the diffusion coefficients for the constituents of the original composition profile. A very large number of variables are involved (the atomic mass of the target, the mass and energy of the implant species, the flux and the total dose, the substrate temperature etc.) so that experimental data are needed despite the existence of relatively well developed models for the implantation process. A major difficulty is that conventional techniques (e.g. electron energy loss spectroscopy) have inadequate resolution for the quantification of any changes in the composition profile of fine scale multilayers. However we have demonstrated that the measurement of 002 dark field intensities in transmission electron microscope images of GaAs / AlxGa1_xAs heterostructures can allow the measurement of the local Al / Ga ratio.

Atomic-scale structural and compositional analyses of Ruddlesden-Popper planar faults in AO-excess SrTiO3 (A = Sr2+, Ca2+, Ba2+) ceramics

2009 ◽  
Vol 24 (8) ◽  
pp. 2596-2604 ◽  
Author(s):  
Sašo Šturm ◽  
Makoto Shiojiri ◽  
Miran Čeh
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Dark Field ◽  
Atomic Scale ◽  
Transmission Electron ◽  
Initial Stage ◽  
Final Microstructure ◽  
Scanning Transmission ◽  
The Matrix ◽  
Annular Dark Field

The microstructure in AO-excess SrTiO3 (A = Sr2+, Ca2+, Ba2+) ceramics is strongly affected by the formation of Ruddlesden-Popper fault–rich (RP fault) lamellae, which are coherently intergrown with the matrix of the perovskite grains. We studied the structure and chemistry of RP faults by applying quantitative high-resolution transmission electron microscopy and high-angle annular dark-field scanning transmission electron microscopy analyses. We showed that the Sr2+ and Ca2+ dopant ions form RP faults during the initial stage of sintering. The final microstructure showed preferentially grown RP fault lamellae embedded in the central part of the anisotropic perovskite grains. In contrast, the dopant Ba2+ ions preferably substituted for Sr2+ in the SrTiO3 matrix by forming a BaxSr1−xTiO3 solid solution. The surplus of Sr2+ ions was compensated structurally in the later stages of sintering by the formation of SrO-rich RP faults. The resulting microstructure showed RP fault lamellae located at the surface of equiaxed BaxSr1-xTiO3 perovskite grains.

scholarly journals FEI Titan 80-300 TEM

2016 ◽  
Vol 2 ◽  
Author(s):  
Andreas Thust ◽  
Juri Barthel ◽  
Karsten Tillmann
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
Spherical Aberration ◽  
Atomic Scale ◽  
Atomic Resolution ◽  
Lens System ◽  
Stage Design ◽  
Precise Positioning ◽  
Transmission Electron ◽  
Wide Range

The FEI Titan 80-300 TEM is a high-resolution transmission electron microscope equipped with a field emission gun and a corrector for the spherical aberration (<em>C</em><sub>S</sub>) of the imaging lens system. The instrument is designed for the investigation of a wide range of solid state phenomena taking place on the atomic scale, which requires true atomic resolution capabilities. Under optimum optical settings of the image <em>C</em><sub>S</sub>-corrector (CEOS CETCOR) the point-resolution is extended up to the information limit of well below 100 pm with 200 keV and 300 keV electrons. A special piezo-stage design allows ultra-precise positioning of the specimen in all 3 dimensions. Digital images are acquired with a Gatan 2k x 2k slow-scan charged coupled device camera.

scholarly journals Dynamic behavior of reversible oxygen migration in irradiated-annealed high temperature superconducting wires

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yi Zhang ◽  
M. W. Rupich ◽  
Vyacheslav Solovyov ◽  
Qiang Li ◽  
Amit Goyal
Keyword(s):  
High Temperature ◽  
Annealing Treatment ◽  
Atomic Scale ◽  
Vacancy Defects ◽  
Superconducting Wires ◽  
High Temperature Superconducting ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Effect Of Oxygen ◽  
Electron Energy Loss

Abstract We use atomically resolved scanning transmission electron microscopy and electron energy loss spectroscopy to determine the atomic-scale structural, chemical and electronic properties of artificial engineered defects in irradiated-annealed high temperature superconducting wires based on epitaxial Y(Dy)BCO film. We directly probe the oxygen vacancy defects in both plane and chain sites after irradiation with 18-meV Au ions. The plane site vacancies are reoccupied during post-annealing treatment. Our results demonstrate the dynamic reversible behavior of oxygen point defects, which explains the depression and recovery of self-field critical current and critical temperature in irradiation-annealing process. These findings reveal the strong effect of oxygen vacancies in different sites on the superconductivity properties of irradiated Y(Dy)BCO film, and provide important insights into defects engineering of 2G HTS coil wires.

SURFACE BONDING STATES OF NANO-CRYSTALLINE DIAMOND BALLS

2001 ◽  
Vol 15 (31) ◽  
pp. 4071-4085 ◽  
Author(s):  
J. L. PENG ◽  
SHAUN BULCOCK ◽  
PETER I. BELOBROV ◽  
L. A. BURSILL
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapour ◽  
Structural Models ◽  
Electronic States ◽  
Surface Structures ◽  
Atomic Scale ◽  
Nano Crystalline ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Electron Energy Loss

The rough surface of nano-crystalline diamond spheres induces surface electronic states which appear as a broadened pre-peak over approx. 15 eV at the C K-edge energy threshold for carbon in the parallel electron energy loss spectrum (PEELS). This appears to be at least partially due to 1s-π* transitions, although typically the latter occupy a range of only 4 eV for the sp2 edge of highly-oriented pyrollytic graphite (HOPG). No π* electrons appear in the conduction band inside the diamond particles, where all electrons are sp3 hybridized. PEELS data were also obtained from a chemical vapour deposited diamond film (CVDF) and gem-quality diamond for comparison with the spectra of nano-diamonds. The density of sp2 and sp3 states on the surface of diamond nano-crystals is calculated for simple structural models of the diamond balls, including some conjecture about surface structures. The results are used to interpret the sp2/sp3 ratios measured from the PEELS spectra recorded as scans across the particles. Surface roughness at the atomic scale was also examined using high-resolution transmission electron microscopy (HRTEM) and electron nano-diffraction patterns were used to confirm the crystal structures.

scholarly journals The origin of striation in the metastable β phase of titanium alloys observed by transmission electron microscopy

2017 ◽  
Vol 50 (3) ◽  
pp. 795-804 ◽  
Author(s):  
Jiangkun Fan ◽  
Jinshan Li ◽  
Yudong Zhang ◽  
Hongchao Kou ◽  
Jaafar Ghanbaja ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Dark Field ◽  
Atomic Scale ◽  
Intermediate Structure ◽  
Atomic Displacements ◽  
Β Phase ◽  
Transmission Electron ◽  
Modulated Structures ◽  
High Resolution Tem

For the β phase of Ti-5553-type metastable β-Ti alloys, striations in transmission electron microscopy (TEM) bright- and dark-field images have been frequently observed but their origin has not been sufficiently investigated. In the present work, this phenomenon is studied in depth from the macroscopic scale by neutron diffraction to the atomic scale by high-resolution TEM. The results reveal that the β phase contains homogeneously distributed modulated structures, intermediate between that of the β phase (cubic) and that of the α phase or the ω phase (hexagonal), giving rise to the appearance of additional diffraction spots at 1/2, 1/3 and 2/3 β diffraction positions. The intermediate structure between β and α is formed by the atomic displacements on each second {110}βplane in the \langle 1{\overline 1}0\rangle_{\beta} direction, whereas that between β and ω is formed by atomic displacements on each second and third {112}βplane in the opposite \langle 11{\overline 1}\rangle_{\beta } direction. Because of these atomic displacements, the {110}βand {112}βplanes become faulted, resulting in the streaking of β diffraction spots and the formation of extinction fringes in TEM bright- and dark-field images, the commonly observed striations. The present work reveals the origin of the striations and the intrinsic correlation with the additional electron reflections of the β phase.

NNN-ISING MODEL SIMULATION OF NANODOMAIN TEXTURES IN RELAXOR-TYPE LEAD SCANDIUM TANTALATE

1993 ◽  
Vol 07 (26) ◽  
pp. 4353-4369 ◽  
Author(s):  
H. QIAN ◽  
J.L. PENG ◽  
L.A. BURSILL
Keyword(s):  
Statistical Physics ◽  
Nearest Neighbor ◽  
Model Simulation ◽  
Dark Field ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Wide Range ◽  
Transmission Electron Microscopic ◽  
Long Range Ordering ◽  
Perovskite Type

Chemical domain textures for lead scandium tantalate (PST) are modelled using Monte Carlo (MCS) and next-nearest-neighbor Ising (NNNI) models. A wide range of degrees of short- and long-range ordering of the (Ta, Sc) atoms occur in ceramic specimens, depending on processing routes. The simulations help us understand and quantify the chemical domain textures, chemical domain wall configurations and other chemical defects which may occur in certain relaxor-type perovskite-type oxides. The results are compared to dark-field transmission electron microscopic observations. Some new types of small defects were discovered. These are described and classified. The results provide a first step towards the development of a microscopic statistical physics framework for analytical theories of the dielectric response of relaxor-type ceramics, where the frequency and temperature variation of the permittivity are due essentially to dipolar-type fluctuations on nanometer scales.

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