Future aberration corrected transmission electron microscopes (TEM) will have a strong impact in materials science, since such microscopes yield information on chemical bonding and structure of interfaces, grain boundaries and lattice defects at an atomic level. Beyond this ...
Energy Citations Database
The Transmission Electron Aberration-corrected Microscope (TEAM) Project For the past several years, five DOE-supported electron beam microscopy efforts, located at Argonne...
Science.gov Websites
TEAM on TV The TEAM Project (Transmission Electron Aberration-Corrected Microscope) Recent Publications from TEAM Why What Who How When and Where DOE In December 1959, physicist...
magnification to compete with Scanning Electron Microscopy Make microscope self-contained for easeC-PEM: Aberration Corrected Photoemission Electron Microscopy J. Nettleton, R. Word, R. Koenenkamp) #12;Corrected Photoemission Electron Microscope (C-PEM) ...
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with transmission electron microscopes (- familiarity with aberration corrected scanning transmission electron-corrected analytical electron microscopes. It is also the home of the world�renowned Lehigh Microscopy SchoolRESEARCH ENGINEER IN ADVANCED ...
At present transmission electron energy loss spectrum (EELS) analysis is only carried out in dedicated research instruments such as transmission electron microscopes (TEMs) or scanning transmission electron microscopes. This article presents a new design of second-order geometric ...
A domestic spherical aberration corrected 300 kV transmission electron microscope named R005, which stands for 0.05 nm resolution, was developed. It has double aberration correctors in probe-forming and image-forming systems for high-resolution scanning transmission electron ...
NASA Astrophysics Data System (ADS)
Imaging Active Sites on Platinum Catalytic Nanoparticles Using Aberration- Corrected Electron of industrial heterogeneous catalysts are often small metallic particles, whose reactivity and selectivity on the extended surfaces of model catalysts can be identified using techniques such as scanning probe microscopy
The lateral resolution of a surface sensitive low-energy electron microscope (LEEM) has been improved below 4 nm for the first time. This breakthrough has only been possible by simultaneously correcting the unavoidable spherical and chromatic aberrations of the lens system. We present an experimental criterion to quantify the ...
PubMed
A brief history of the development of direct aberration correction in electron microscopy is outlined starting from the famous Scherzer theorem established in 1936. Aberration correction is the long story of many seemingly fruitless efforts to improve the resolution of ...
Scanning confocal electron microscopy (SCEM) is a new imaging mode in electron microscopy. Spherical aberration corrected electron microscope instruments fitted with two aberration correctors can be used in this mode which provides improved depth resolution and selectivity ...
ANL Electron Microscopy Center iTEAM Project EMail List Subscription Form * Your Name: First: Middle: Last: * Your Affiliation: Please do not use abbreviations * E-mail address:...
One of the problems associated with building any aberration-corrected electron microscope objective lens lies in the difficulty of obtaining a sufficiently short focal length. A corrector device which can be used with a conventional magnetic objective len...
National Technical Information Service (NTIS)
The authors demonstrate that confocal imaging trajectories can be established in a transmission electron microscope fitted with two spherical aberration correctors. An atomic-scale electron beam, focused by aberration-corrected illumination optics, is directly imaged by a second aberration-corrected system. The ...
Following the pioneering development of atomic resolution in-situ environmental TEM (ETEM) for direct probing of gas-solid reactions, recent developments are presented of dynamic real time in-situ studies at the Angstrom level in an aberration corrected electron microscope. The in-situ data from Pt-Pd nanoparticles ...
We visualized lithium atom columns in LiV?O? crystals by combining scanning transmission electron microscopy with annular bright field (ABF) imaging using a spherical aberration-corrected electron microscope (R005) viewed from the [110] direction. The incident electron beam was coherent with a ...
Recent instrumental developments have enabled greatly improved resolution of scanning transmission electron microscopes (STEM) through aberration correction. An additional and previously unanticipated advantage of aberration correction is the greatly improved depth ...
Mapping of Phase Segregation at CMR Grain Boundaries in the Scanning Transmission Electron Microscope "The in the Scanning Transmission Electron Microscope M. Varela*, V. Pe�a**, Z. Sefrioui**, A. R. Lupini*, J. Aberration correction in the Scanning Transmission ...
A new ultrahigh-resolution photoemission electron microscope called PEEM3 is being developed and built at the Advanced Light Source (ALS). An electron mirror combined with a much-simplified magnetic dipole separator is to be used to provide simultaneous correction of spherical and chromatic aberrations. It is installed on an ...
A new ultrahigh-resolution photoemission electron microscope called PEEM3 is being developed and built at the Advanced Light Source (ALS). An electron mirror combined with a much-simplified magnetic dipole separator is to be used to provide simultaneous c...
Design of a new aberration corrected Photoemission electron microscope PEEM3 at the Advanced Light Source is outlined. PEEM3 will be installed on an elliptically polarized undulator beamline and will be used for the study of complex materials at high spatial and spectral resolution. The critical components of PEEM3 ...
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A time-of-flight concept that dynamically corrects for chromatic aberration effects in scanning electron microscopes (SEMs) is presented. The method is predicted to reduce the microscope's chromatic aberration by an order of magnitude. The scheme should significantly improve the spatial resolution of low-voltage scanning ...
The resolving power of high-resolution transmission electron microscopes is characterized by the information limit, which reflects the size of the smallest object detail observable with a particular instrument. We introduce a highly accurate measurement method for the information limit, which is suitable for modern aberration-corrected ...
Lowering the electron energy in the transmission electron microscope allows for a significant improvement in contrast of light elements and reduces knock-on damage for most materials. If low-voltage electron microscopes are defined as those with accelerating voltages below 100 kV, the ...
Lowering the electron energy in the transmission electron microscope allows for a significant improvement in contrast of light elements, and reduces knock-on damage for most materials. If low-voltage electron microscopes are defined as those with accelerating voltages below 100 kV, the ...
PubMed Central
is capable of obtaining gas samples inside the confined spaces of reactors like automotive cata- lysts, fuel current ACC Automotive Composites Consortium ACEM aberration-corrected electron microscope ACERT advanced National Renewable Energy Laboratory NTRC National Transportation Research Center OEM original equipment
This paper presents our recent progress on the application of reconfigurable logic technology to intelligent human sensing. First, hardware specialization technique is presented to realize small and fast preprocessor based on reconfigurable logic devices. Second, a load balancing technique for heterogeneous systems is introduced. Then, a real-time aberration ...
The design and construction of a double-hexapole aberration corrector has made it possible to build the prototype of a spherical-aberration corrected transmission electron microscope dedicated to high-resolution imaging on the atomic scale. The corrected instrument, a Philips CM200 FEG ST, has an information limit ...
We have successfully developed a spherical aberration (Cs)-corrected electron microscope for probe- and image-forming systems using hexapole correctors. The performance of the microscope has been evaluated experimentally. The point resolution attained using the image-forming Cs-corrector is better than 0.12 nm. For scanning ...
Information from imaging and diffraction planes, or real and reciprocal spaces, of transmission electron microscopes (TEM) can be combined using iterative transformation algorithms to reconstruct the complex wave function, to improve image resolution and to remove residual aberrations in the case of aberration ...
The optimal lens parameters for incoherent imaging using third and fifth-order aberration-corrected electron microscopes are derived analytically. We propose simple models for the point spread function (PSF) and transfer function that give analytic formulae for the lateral resolution and depth resolution. We also derive an analytic ...
As a new microscopic method to reveal lithium ion behavior in lithium ion batteries, we demonstrated that lithium atoms in the diffusion channel of the spinel structure (LiV2O4 crystal) were visualized and their number was countable one-by-one by using annular bright field imaging method in conjunction with a spherical aberration ...
In order to understand the mechanism of Cu clustering and Ni effects on Cu clusters, a sub-nano scale structural and elemental analysis of Cu-bearing steels was carried out through an aberration corrected scanning transmission electron microscope. Based on systematic observation condition adjustment by changing the ...
The aberration of a multipole Wien filter for energy-filtered x-ray photoemission electron microscopy was analyzed and the optimized Fourier components of the electric and magnetic fields for the third-order aperture aberration corrections were obtained. It was found that the third-order aperture aberration ...
The revolution in nanoscale science and technology requires instrumentation for observation and metrology - we must be able to see and measure what we build. Because nano-devices operate on the level of a few molecules, or even a few atoms, accurate atomic-scale imaging is called for. High-resolution aberration-corrected electron ...
The technique of X-ray energy dispersive spectroscopy (XEDS) spectrum imaging in a dedicated scanning transmission electron microscope (STEM) is discussed in relation to its applicability to bimetallic nanoparticles. It is shown that the recent availability of aberration corrected microscopes ...
Aberration corrected electron optics allow routine acquisition of high-spatial resolution spectroscopic images in the scanning transmission electron microscope, which is important when trying to understand the physics of transition metal oxides such as manganites. The physical properties of ...
Electron energy loss (EEL) spectroscopy and high angle annular dark field (HAADF) imaging in aberration-corrected electron microscopes are powerful techniques to determine the chemical composition and structure of materials at atomic resolution. We have implemented Smart Acquisition, a flexible system of scanning transmission ...
The resolution-limiting aberrations of round electromagnetic lenses can now be successfully overcome via the use of multipole element 'aberration correctors.' The installation and performance of a hexapole-based corrector (CEOS GmbH) integrated on the probe-forming side of a JEOL 2200FS FEG STEM/TEM is described. For the resolution of the microscope not to be ...
Vacancies (VCu, VIn) and substitutional atoms (InCu, CuIn) in CuInSe2 crystal, which is the key semiconductor material for thin film solar cell applications, were directly observed by 300kV aberration-corrected high angle annular dark field scanning transmission electron microscope (HAADF-STEM). The atomic columns of Cu, In and Se were ...
Aberration-corrected scanning transmission electron microscopes (STEMs) provide sub-Angstrom lateral resolution; however, the large convergence angle greatly reduces the depth of field. For microscopes with a small depth of field, information outside of the focal plane quickly becomes blurred and less defined. It ...
Recent and ongoing improvements in aberration correction have opened up the possibility of depth sectioning samples using the scanning transmission electron microscope in a fashion similar to the confocal scanning optical microscope. We explore questions of principle relating to image ...
In this paper we report the use of adaptive optics to correct for sample induced aberrations in optical microscopy, crucially comparing individual pixel-by-pixel correction against a single correction for an entire optical section. Sample induced optical aberrations in slices of rat brain tissue were corrected with a deformable membrane mirror. Using axial resolution measurements, we demonstrate ...
The ability to correct the aberrations of the probe-forming lens in the scanning transmission electron microscope provides not only a significant improvement in transverse resolution but in addition brings depth resolution at the nanometer scale. Aberration correction therefore opens up the possibility of 3D ...
Following the invention of electron optics during the 1930s, lens aberrations have limited the achievable spatial resolution to about 50 times the wavelength of the imaging electrons. This situation is similar to that faced by Leeuwenhoek in the seventeenth century, whose work to improve the quality of glass lenses led directly to his discovery of the ...
The resolution of electron energy loss spectroscopy (EELS) is limited by delocalization of inelastic electron scattering rather than probe size in an aberration corrected scanning transmission electron microscope (STEM). In this study, we present an experimental ...
The transmission electron microscope (TEM) has evolved into a highly sophisticated instrument that is ideally suited to the characterization of advanced materials. Atomic-level information is routinely accessible using both fixed-beam and scanning TEMs. This report briefly considers developments in the field of atomic-resolution ...
Aberration correction leads to a substantial improvement in the directly interpretable resolution of transmission electron microscopes. Correction of the aberrations has been achieved electron-optically through a hexapole-based corrector and also indirectly by computational analysis of a focal ...
In the structural characterization of thin specimens by projection (atomic column) imaging, the revolutionary development of aberration-corrected electron microscopy has already brought significant improvements not only in spatial resolution but also in improved image contrast. Some highlights from the symposium are summarized. Despite the purchasing and operating costs as ...
Chemical mapping at atomic-column resolution by energy-dispersive x-ray spectroscopy in a spherical aberration-corrected scanning transmission electron microscope (STEM) has been demonstrated for the 1.47-A dumbbell structure in InGaAs. The structural imaging and the chemical information in the two-dimensional map are directly ...
of carbon monoxide on nanoscale facets. Aberration-corrected scanning transmission electron microscopy techniques have been used to elucidate the atomic structures of the active...
The grooved surface of an aberration-corrected holographic model grating is sensed by utilizing the sensing head of a scanning tunneling microscope. The sensing head is mechanically connected to a blazing type stylus for replicating the groove pattern of ...
The last decade witnessed the rapid development and implementation of aberration correction in electron optics, realizing a more-than-70-year-old dream of aberration-free electron microscopy with a spatial resolution below one angstrom [1-9]. With sophisticated aberration correctors, modern ...
The short depth of focus of aberration-corrected scanning transmission electron microscopes (STEMs) could potentially enable 3D reconstruction of nanomaterials through acquisition of a through-focal series. However, the contrast transfer function of annular dark-field (ADF)-STEM depth sectioning has a missing-cone problem similar to that of tilt-series ...
The "delocalization" of inelastic scattering is an important issue for the ultimate spatial resolution of innershell spectroscopy in the electron microscope. It is demonstrated in a nonlocal model for electron energy loss spectroscopy (EELS) that delocalization of scanning transmission electron microscopy (STEM) ...
Aberration correction of the probe forming optics of the scanning transmission electron microscope has allowed the probe-forming aperture to be increased in size, resulting in probes of the order of 1 A in diameter. The next generation of correctors promise even smaller probes. Improved spectrometer optics also ...
Using a highly coherent focused electron probe in a fifth-order aberration-corrected transmission electron microscope, we report on resolving a crystal spacing less than 50 pm. Based on the geometrical source size and residual coherent and incoherent axial lens aberrations, an electron probe is ...
The attainable specimen resolution is determined by the instrumental resolution limit d(i) and by radiation damage. Solid objects such as metals are primarily damaged by atom displacement resulting from knock-on collisions of the incident electrons with the atomic nuclei. The instrumental resolution improves appreciably by means of aberration ...
Voids adjacent to cubic (ZnS-type) and hexagonal (NiAs-type) Mn-rich nanocrystals are characterized using aberration-corrected transmission electron microscopy in an annealed Ga0.995Mn0.005As magnetic semiconductor specimen grown by molecular beam epitaxy. Nanobeam electron diffraction measurements suggest that the nanocrystals exhibit ...
Using a highly coherent focused electron probe in a 5th order aberration-corrected transmission electron microscope, we report on resolving a crystal spacing less than 50 pm. Based on the geometrical source size and residual coherent and incoherent axial lens aberrations, an electron probe is ...
The successful correction of third-order and, more recently, fifth-order aberrations has enormously enhanced the capabilities of the scanning transmission electron microscope (STEM), by not only achieving record resolution, but also allowing near 100% efficiency for electron energy loss spectroscopy, and higher currents for ...
Modern transmission electron microscopes (TEM) allow utilizing the spherical aberration coefficient as an additional free parameter for optimizing resolution and contrast. By tuning the spherical aberration coefficient of the objective lens, isolated nitrogen atom columns as well as the Si-N dumbbells within the six-membered ring were imaged in beta-Si3N4 ...
Using a fifth-order aberration-corrected scanning transmission electron microscope, which provides a factor of 100 increase in signal over an uncorrected instrument, we demonstrated two-dimensional elemental and valence-sensitive imaging at atomic resolution by means of electron energy-loss spectroscopy, with ...
The performance of the conventional low-energy CD-SEM is limited by the aberrations inherent in the probe forming lens. Multi-pole correctors are now available which can reduce or eliminate these aberrations. An SEM equipped with such a corrector offers higher spatial resolution and more probe current from a given electron source, and other aspects of the optical performance ...
The precise atomic structure of activated carbon is unknown, despite its commercial importance. Here we show that the structure of a commercial activated carbon can be imaged directly using aberration corrected transmission electron microscopy. Images are presented both of the as-produced carbon and of the carbon following heat- ...
High resolution local structure information is revealed when the complex exit wavefunction is restored from a series of transmission electron microscope (TEM) images. Aberration corrected image data sets allow high spatial frequency information to be restored but this is often at the expense of lower spatial ...
Quantum antidots (a vacancy cluster) have been proposed to account for the non-linear optical behavior of magnesium oxide (MgO) dispersed with Au nanoclusters [1,2]. In this paper, we provide convincing evidence, based on direct observation using high-angle annular dark-filed imaging in aberration corrected scanning transmission ...
with a confocal microscope, the images obtained are dimmer and suffer from degraded lateral and, more importantly�6003. Gu, M. (1996) Principles of Three-Dimensional Imaging in Confocal Microscopes. World Scientific 23 August 2000 SHORT COMMUNICATION Adaptive aberration correction in a two-photon ...
An automated technique for the mapping of nanocrystal phases and orientations in a transmission electron microscope (TEM) is described. It is based on the projected reciprocal lattice geometry that is extracted from electron diffraction spot patterns. The required hardware allows for a scanning-precession movement of the primary ...
Monodisperse icosahedral Au nanoparticles were synthesized using one step protocol. The morphology and structural characteristics of the icosahedral Au nanoparticles with uniform size were studied in detail using ultra-high resolution scanning electron microscope (SEM) FEG Hitachi S-5500 (0.4 nm at 30 kV) with BF/DF Duo-STEM detector, high resolution ...
The VG Microscopes 100 kV and 300 kV scanning transmission electron microscopes at Oak Ridge National Laboratory were equipped with Nion aberration correctors several years ago. This chapter reviews our experience with these correctors, specifically, the reduction in probe size by more than a factor of two and the associated benefits ...
Graphene is a crystalline single layer of carbon atoms that can be viewed as an individual atomic plane extracted from graphite. Freely suspended mono-layer graphene is the thinnest possible membrane that is conceivable with currently known materials. Yet, it is remarkably stable under electron irradiation and thus opens unprecedented opportunities for ...
To achieve the highest performance with today's generation of aberration-corrected electron microscopes, it is increasingly evident that the environment of the facility in which the microscope is installed must be considered an integral component of the microscopy program. Such instruments are the world's best ...
Electron tomography is a valuable 3D characterization technique, so far limited to a nanometer scale resolution. This paper intends to explore the extension of the technique to the atomic scale. Computer simulations of three HREM technologies are performed on a CeO2 crystal and the effects of the voltage, focus spread and aberration ...
A high-resolution aberration-corrected photoemission electron microscope (PEEM3) will be installed on an undulator beamline at the Advanced Light Source at the Lawrence Berkeley National Laboratory. The aim of this instrument is to provide a substantial flux and resolution improvement by employing an electron ...
We report on a novel aberration correction technique that uses the sequential combination of two different aberration measurement methods to correct for setup-induced and specimen-induced aberrations. The advantages of both methods are combined and, thus, the measurement time is strongly reduced without loss of accuracy. The technique is implemented using ...
Compression testing of micro-pillars has recently been of great interest to the small-scale mechanics community. Previous compression tests on single crystal Mo alloy micro-pillars produced by directional solidification of eutectic alloys showed that as-grown pillars yield at strengths close to the theoretical strength while pre-strained pillars yield at considerably lower stresses. In addition, ...
Transmission electron microscope (TEM) images recorded under tilted illumination conditions transfer higher spatial frequencies than axial images. This super resolution information transfer is highly directional in a single image, but can be extended in all directions through the use of complementary beam tilts during exit wave function reconstruction. We ...
A new high-resolution aberration corrected photoemission electron microscope (PEEM3) will be installed on an undulator beam line at the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory. The aim of this instrument is to provide a substantial flux and resolution improvement by employing an ...
The implementation of aberration correction for the scanning transmission electron microscope (STEM) enables the use of larger probe-forming apertures, improving the transverse resolution significantly and also bringing depth resolution at the nanometer scale. This opens up the possibility of three-dimensional ...
Industrial catalysts with State-of-the-art Aberration-corrected Transmission Electron Microscopy Petra Specht 66 Auditorium 2:25pm Single Crystal Dynamics by a TEM Haimei...
A human fundus transverse microscopic imaging system based on a MEMS deformable membrane mirror was developed. A 37 element small MEMS deformable membrane mirror was used as wave front corrector in this system. Wavefront errors were measured by a Hartman-Shack wave front sensor which contains 127 micro lens lets. After the wavefront error of human eye had been corrected by the ...
The physical thickness of silicon oxynitride gate dielectric materials currently in development have dimensions in the range of 15-20 Angstrom ({approx}6-8 oxygen atoms), while approaching the dielectric constant equivalent oxide thickness (EOT) of 12 Angstrom silicon dioxide. These structures present serious challenges in meeting stringent requirements within the semiconductor industry for ...
We examine the effects of aberrations induced by a refractive index mismatch on the signal level and resolution of single-photon (1-p) and two-photon (2-p), conventional and confocal scanning microscopes. In particular, we consider the aberrations introduced by an interface between oil/glass and water. Resolution is defined in terms of enclosed fluorescence, rather than ...
Gold nanoparticles have a high catalytic activity for CO oxidation at low temperatures providing they remain less than 5nm in diameter. Their structure and stability and the growth processes that occur during heating have been investigated using Angstrom resolution in-situ double aberration corrected transmission electron microscopy ...
As part of a feasibility study into the use of novel electron detectors for X-ray photoelectron emission microscopes (XPEEM), we have characterised the imaging performance of a back-illuminated monolithic active pixel sensor (MAPS) operating under both integrating and counting modes for electrons in the energy range 10-20 keV. For ...
High spatial resolution chemical analysis and imaging of a CrAlYN/CrN multi-layer coating was performed using sub-nanometer probe electron energy loss spectroscopy in a spherical aberration corrected scanning transmission electron microscope. Analysis indicated the CrN layers to be near ...
Aberration-corrected scanning transmission electron microscopes (STEMs) can now produce electron probes as small as 1 {angstrom} at 60 keV. This level of performance allows individual light atoms to be imaged in various novel materials including graphene, monolayer boron nitride, and carbon nanotubes. Operation at ...
We demonstrate a multimodal, multifocal, differential nonlinear optical microscope, which is equipped with a pair of deformable mirrors and a Shack-Hartmann sensor for dynamic wavefront manipulation. The optical wavefronts of a home built Yb:KGW femtosecond (1028 nm) laser-beams are engineered to perform multidepth focusing in differential mode with simultaneous corrections ...
Most implementations of adaptive optics in microscopes have not employed a wavefront sensor, but have instead used sensorless aberration correction methods. In these systems, the aberration is determined indirectly through the optimisation of a quality metric, such as image intensity. We explain the principles behind this approach and ...
... Accession Number : ADA319052. Title : Demonstrating Optical Aberration Correction With a Mems Micro-Mirror Device. ...
DTIC Science & Technology
In many scientific and medical applications, such as laser systems and microscopes, wavefront-sensor-less (WFSless) adaptive optics (AO) systems are used to improve the laser beam quality or the image resolution by correcting the wavefront aberration in the optical path. The lack of direct wavefront measurement in WFSless AO systems imposes a challenge to achieve efficient ...
In the 4 years since the previous meeting in the SALSA series, aberration correction has progressed from a promising concept to a powerful research tool. We summarize the factors that have enabled 100-120kV scanning transmission electron microscopes to achieve sub-A resolution, and to increase the current available ...
Electron lenses are extremely poor: if glass lenses were as bad, we should see as well with the naked eye as with a microscope! The demonstration by Otto Scherzer in 1936 that skillful lens design could never eliminate the spherical and chromatic aberrations of rotationally symmetric electron lenses was therefore most unwelcome and the ...
We present details of the new electron holographic dark-field technique (HoloDark) for mapping strain in nanostructures. A diffracted beam emanating from an unstrained region of crystal is interfered (with the aid of an electrostatic biprism) with a diffracted beam from the strained region of interest. Geometric phase analysis (GPA) of the holographic fringes determines the ...
Gold nanoclusters dispersed in single crystal TiO?, MgO, and SrTiO? have been prepared by ion implantation at 300 K - 975 K and subsequent annealing at 1275 K for 10 hours. High resolution transmission electron microscopy and high-angle-annular-dark-field (HAADF) imaging in aberration corrected scanning transmission ...
The HTML User Program continued to work with industrial, academic, and governmental users this year, accepting 92 new projects and developing 48 new user agreements. Table 1 presents the breakdown of these statistics. Figure 1 depicts the continued growth in user agreements and user projects. You will note that the total number of HTML proposals has now exceeded 1000. Also, the large number of new ...
Au nanoclusters dispersed in single crystal TiO2 and SrTiO3 have been prepared by ion implantation at 300 and 975 K and subsequent annealing at 1275 K for 10 hours. High resolution transmission electron microscopy and high-angle-annular-dark-field (HAADF) imaging in an aberration corrected scanning transmission ...
The polarization of the ferroelectric BiFeO(3) sub-jected to different electrical boundary conditions by heterointerfaces is imaged with atomic resolution using a spherical aberration-corrected transmission electron microscope. Unusual triangular-shaped nanodomains are seen, and their role in providing polarization closure is ...
The effect of the chromatic aberration (C(c)) coefficient in a spherical aberration (C(s))- corrected electromagnetic lens on high-resolution high-angle annular dark field (HAADF) scanning transmission electron microscope (STEM) images is explored in detail. A new method for precise determination of the C(c) coefficient is demonstrated, requiring ...
In this work, we structurally characterize defects, grain boundaries, and intergrowth phases observed in various Mo-V-O materials using aberration-corrected high-angle annular dark-field (HAADF) imaging within a scanning transmission electron microscope (STEM). Atomic-level imaging of these preparations clearly shows domains of the ...
We have developed new STEM instrumentation with a cold field emission source (Hitachi HD-2700) in order to perform structural characterization and elemental mapping at the atomic level. The instrument utilises the CEOS GmbH (Germany, managing director: Dr. Max Haider) aberration corrector. The accelerating voltage range is between 80 kV and 200 kV. The cold field emission source proves to be the ...
Aberration correction in the scanning transmission electron microscope combined with electron energy loss spectroscopy allows simultaneous mapping of the structure, the chemistry and even the electronic properties of materials in one single experiment with spatial ...
As the thin film materials used in electronic and optical applications continue to decrease in thickness to the nano-scales, marked changes in functional properties are expected to occur due to changes in crystal structure of these materials. Therefore, such multilayer systems have been of considerable interest due to the ability to control properties by engineering the ...
Transition metal chalcogenides like MoS2 or WS2 are quasi-two dimensional (2D) compounds. Similar to carbon, transitional metal chalcogenides also form close caged structures known as inorganic fullerenes (IF) and nanotubes (INTs). We have sought to use probe aberration corrected electron microscopy for elucidating some important ...
The recent advent of a novel design of in situ heating technology for electron microscopes has permitted unprecedented control of elevated temperature studies of catalytic materials, particularly when coupled with the sub-Angstr�m imaging performance of a modern aberration-corrected scanning transmission electron ...
Owing to its solubility compared to graphene, graphene oxide (GO) has become popular in recent years as a potentially scalable precursor to graphene in devices. After the GO's oxidation and defects are chemically and thermally removed, reduced and annealed graphene oxide (raGO) remains. Using aberration-corrected transmission electron microscopy, we ...
Inclusion of spatial incoherence has been shown to give quantitative agreement between non-aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images and theoretical simulations. Here we show that, using the same approach, a significant improvement in the correlation between calculated and experimental normalized ...
Inclusion of spatial incoherence has been shown to give quantitative agreement between non-aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images and theoretical simulations. Here we show the same approach is valid for aberration-corrected probes, by fitting theoretical and experimental normalized integrated ...
Aberration correted electron microscopy (ACEM) has improved resolution to sub-angstrom regime, which allows us to study materials with light elements, with dopants and defects, and with electronic, magnetic and optical functions. Developments of ACEMs and applications that undertaken in the world are briefly reviewed, being focused particularly on 50 pm ...
The structure of DNA has been the subject of intense and continuous study for over 56 years [1, 2, 3]. Studies using electron and x-ray diffraction from crystals of DNA have provided a wealth of structural information on sequences in different conformations [4, 5], but to date individual bases in single DNA molecules have not been resolved [6, 7]. Here we use standard and ...
-tunable optical and electronic properties for applications in photo- voltaics,1-3 photocatalysis,4-7 bioassays,3: RBS data used to calculate the ratio of Cd to Se for the HDA CdSe nano- crystals. This material subtle details about the shape and faceting of nano- crystals with near sub-angstrom precision
Chromatic and spherical aberration-corrected atomic-resolution transmission electron microscopy combined with density-functional theory calculations is employed to elucidate the stability and dynamics of admolecules on suspended graphene. The results presented provide evidence that the interaction between the molecules and hydrogen adatoms leads to a ...
Direct atomic displacement mapping at ferroelectric interfaces by aberration corrected scanning transmission electron microscopy(STEM) (a-STEM image, b-corresponding displacement profile) is combined with Landau-Ginsburg-Devonshire theory to obtain the complete interface electrostatics in real space, including separate estimates for ...
Electron optical aberrations play important roles in high voltage electron optical instruments used for lithography (SCALPEL) and high-resolution electron microscopy (HREM). In this thesis, we developed new theoretical approaches for the aberration corrections in these two important fields. In ...
One of the most challenging tasks for high-resolution electron microscopy is the investigation of the atomic structure of defects, interfaces, and grain boundaries. In particular, the application of thin films in electronic devices requires detailed knowledge of the microstructure, which can influence the electronic and optical ...
John Cowley pioneered use of transmission electron microscopy (TEM) for high-resolution imaging and helped spur improvements in resolution that enabled researchers to pinpoint the positions of all but the lightest atoms within a crystal structure. Sub-{angstrom} capabilities allow imaging of even the lightest atoms. Initially achieved with software ...
Higher-order aberrations correction can improve visual performance of human eye to some extent. To evaluate how much visual benefit can be obtained with higher-order aberrations correction we developed an adaptive optics vision simulator (AOVS). Dynamic real time optimized modal compensation was used to implement ...
ZnO with additions of Fe(2)O(3) or In(2)O(3) shows characteristic inversion domain structures. ZnO domains are separated by two types of inversion domain boundaries (IDBs): basal b-IDBs parallel to (0001) planes, and complementary pairs of three possible variants of pyramidal p-IDBs parallel to {21�1�5} lattice planes. The structure and composition of IDBs were investigated in a sophisticated ...
Scanning transmission electron microscopy (STEM) in combination with electron energy loss spectroscopy (EELS) has proven to be a powerful technique to study buried perovskite oxide heterointerfaces. With the recent addition of 3^rd order and now 5^th order aberration correction, which provides a factor of 100x ...
