bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is your scanning electron microscope Hi‐Fi?
Authors: Vladár András E. , Postek Michael T. , Davilla Scott D. 
Published: June 2010

AbstractThe scanning electron microscope (SEM) historically has been used mainly as an image‐producing device and, in spite of certain obvious and sometimes serious electronics problems, serves in this function as an acceptable and effective instrument for many applications. Today, the SEM is being used in areas other than imaging. The major area of current use and of concern of this Workshop paper is SEM‐based metrology. SEM‐based metrology is of great interest to the microelectronics industry, and for this industry, measurement accuracy and repeatability issues have become paramount. This paper presents a short description of some of the electrical properties of different components of an SEM which can seriously affect its performance as a metrology tool. These include the electronics associated with the formation of the electron beam and scanning circuitry, the electron detectors, the video signal chain, and the analog‐to‐digital (AD) and digital‐to‐analog (DA) conversion circuits. This discussion relates the possible influences generated by these components to the detected and observed signal. This paper also includes the concept that computer modeling of the SEM image, with Monte Carlo or other techniques, must be done completely in order to be meaningful. Modeling just the electron beam/sample interactions alone only deals with a portion of the issues. Any modeling must include the shortcomings of the real, nonideal measuring tool. By knowing the electrical characteristics and possible imperfections caused by the different parts of an SEM, a more accurate comparison of the measured and calculated signal can be made. One practical example is presented which demonstrates how it is possible to improve the agreement between calculated and measured signals.
Atomic and magnetic force microscopy imaging of thin‐film recording heads
Authors: Chim W. K. 
Published: June 2010

AbstractInvestigations on the use of the scanning probe microscope (SPM) in the atomic force microscopy (AFM) mode for topography imaging and the magnetic force microscopy (MFM) mode for magnetic imaging are presented for a thin‐film recording head. Results showed that the SPM is suitable for imaging the surface profile of the recording head, determining the width of the pole gap region, and mapping the magnetic field patterns of the recording head excited under current bias conditions of different polarity. For the cobalt sputter‐coated tips used in MFM imaging, it was found that the magnetic field patterns obtained under different polarities of the current bias to the recording head were similar. This can be explained by the nature of the thin‐film MFM tip, in which the direction of the tip magnetic moment can follow the stray magnetic field of the sample as the current bias to the recording head reverses in direction.
Charging control using pulsed scanning electron microscopy
Authors: Wong W. K. , Phang J. C. H. , Thong J. T. L. 
Published: June 2010

AbstractThis paper describes a novel method to observe highly charging specimens at high‐beam voltages without specimen preparation. It is found that the technique greatly reduces charging artifacts such as image shift, astigmatism, and defocussing without sacrificing image quality. Images obtained of uncoated specimens are found to be comparable to gold‐coated specimens and without exhibiting charging effects. The technique also allows the study of charge distribution effects in specimen charging of which very little understanding exists, particularly as far as the spatial and time‐dependent properties of charging are concerned.
Simple modifications for accurate high‐temperature gas exposures using scanning electron microscopy
Authors: Poston James A. 
Published: June 2010

AbstractRelatively low‐cost modifications to standard commercial scanning electron microscopes (SEM) that allow accurate exposure of sample(s) to noncorrosive gases at ambient and high temperatures are outlined. Energy‐dispersive spectroscopic analysis of sample(s) exposed to noncorrosive gases at high temperatures is demonstrated. Gas exposure is limited to pressures of less than 10−4 torr (1.33 × 10−2 Pa) as a result of limitations on SEM system operation and SEM safety interlocks. Gases are limited to noncorrosive types as a result of potential damage to system detection devices and internal mechanical parts.
Morphologic and cathodoluminescence studies of diamond films by scanning electron microscopy
Authors: Saparin G. V. , Obyden S. K. 
Published: June 2010

AbstractUsing recent papers on scanning electron microscopy (SEM) of chemical vapor deposition (CVD) diamond films, two analytical applications of the SEM are discussed: the morphologic investigations (secondary electron emission mode) and the recognition of impurities and defects [cathodoluminescence (CL) mode]. Studies of CVD diamond films by SEM demonstrate that the morphologies of these films are affected by synthesis conditions, especially by substrate temperature, methane concentration, and total pressure in the reactor. CL spectra and images are useful tools for clarifying the relationship between emission centers and different types of defects generated during the process of diamond crystal growth. The paper shows that the investigations of the morphology, crystallinity, local CL emission, as well as the surface distribution of CL spectra on CVD diamond films by SEM led to the correlative information for quality estimation of films in comparison with natural diamond.
Characterization of electron scattering in solids using a generalized walk
Authors: Gauvin Raynald 
Published: June 2010

AbstractA new method to characterize electron scattering in solids is presented. This method is based on the concept of fractal geometry leading to a generalized walk. A criterion is presented to validate the applicability of this method. This method is applied to random walks with variable mean free path to validate it. Finally, this method is applied to the diffusion of incident electrons in solids of gold and carbon to characterize the transition between persistent and random walk processes describing the diffusion of the electrons in these materials.
Analysis of sections of implanted macroporous calcium phosphate bone substitutes by proton‐induced x‐emission method and energy‐dispersive spectrometry
Authors: Frayssinet P. , Braye F. , Weber G. 
Published: June 2010

AbstractThe osseointegration of porous calcium phosphate ceramics once implanted evolves in several stages. The mechanism of integration of such material usually is evaluated by histologic analysis. The trace elements present in bone can be detected in the ceramic and help to provide a semiquanti‐tative evaluation of osseointegration. Two different methods of microanalysis, energy‐dispersive spectrometry (EDS) and proton induced x‐emission (PIXE) were used in this study to determine the appearance of trace elements (Zn, Sr, and Fe) present in bone at the implantation site containing the ceramic. Porous HA‐ceramic cylinders were implanted in the cortical bone of sheep femurs for periods ranging from 2 to 36 weeks. Thick sections of the implant‐containing bone were made at the end of the implantation period. A scanning line with proton or electron impacts 0.5 mm apart was plotted from the edges of the cortical bone across the implanted ceramic and the resulting x‐ray spectra were determined. Following EDS analysis, the sections were surface‐stained, observed under a light microscope, and the pore volume occupied by bone tissue was measured. The spectra obtained by PIXE method showed two regions for each element characterising either the bone tissue or the ceramic. Zinc and strontium present in the bone tissue, but absent from the ceramic, appeared 8 and 12 weeks after implantation, respectively. The concentration of iron present in the implant decreased with time. EDS showed no significant level of either element in the bone or the ceramic. Histologic observation revealed that immature bone invaded the pores of the outer layer of the ceramic as early as 2 weeks after implantation. The ceramics were totally osseoin‐tegrated 20 weeks after implantation, although ceramic degradation continued for longer. In this experiment, the PIXE method was apparently sufficiently sensitive for monitoring the amount of trace element appearing in bone‐implanted material.
Three‐dimensional reconstruction of aqueous channels in human trabecular meshwork using light microscopy and confocal microscopy
Authors: Camp Jon J. , Hann Cheryl R. , Johnson Douglas H. , Tarara James E. , Robb Richard A. 
Published: June 2010

AbstractConventional two‐dimensional imaging of the trabecular meshwork (TM) provides limited information about the size, shape, and interconnection of the aqueous channels within the meshwork. Understanding the three‐dimensional (3‐D) relationships of the channels within this tissue may give insight into its normal function and possible changes present in the eye disease glaucoma. The purpose of our study was to compare laser scanning confocal microscopy with standard 1 μm Araldite‐embeddedhistologic sections for 3‐D analysis of the trabecular meshwork. In addition, the study was done to determine whether computerized 3‐D reconstruction could isolate the fluid spaces of the trabecular meshwork and determine the size of interconnections between the fluid spaces. Confocal microscopy appears comparable to 1 μm Araldite‐embedded tissue sections and has the advantage of inherent registration of the serial tissue sections. Three‐dimensional reconstruction allowed the isolation of the fluid spaces within the trabecular meshwork and revealed the presence of numerous interconnections between larger fluid spaces. The distribution of these interconnections was randomly arranged, with no predilection for specific regions within the trabecular meshwork. This distribution of constrictions and “expansion chambers” may provide a clue to the mechanism by which subtle histologic changes are associated with increased ocular pressure in glaucoma.
Inexpensive digital imaging?
Authors: Postek Michael T. , Vladar Andras E. 
Published: June 2010

AbstractThe capture of digital images through the use of a frame grabber provides tremendous advantages to scanning electron microscopy. Accessory frame grabbers can range in price from very inexpensive to several thousand dollars. This work investigates the application of one inexpensive “consumer product” frame grabber which has recently been introduced to scanning electron microscope (SEM) imaging. The application of this frame grabber to the SEM as a low‐cost, entry‐level digital imaging tool is explored, and its performance is compared with a more expensive system.
Curvilinear finite element mesh generation for electron gun simulation
Authors: Khursheed Anjam 
Published: June 2010

AbstractMesh generation is an integral part of the finite element simulation of electron guns. This paper shows that curvilinear meshes are the ideal type of mesh to use, both in terms of accuracy and speed of computation, and presents a numerical method to generate quasi‐curvilinear meshes for a wide variety of electron gun structures.
The method of increasing COMPO contrast by linearization of backscattering characteristic η =f(Z)
Authors: Kaczmarek Danuta 
Published: June 2010

AbstractThe backscattered electron signal (BSE) in the scanning electron microscope (SEM) has been used for investigation of a specimen surface composition (COMPO mode). Creation of a material composition map is difficult because the dependence of backscattering coefficient η on the atomic number Z for Z > 40 is nonlinear. The method of increase in SEM resolution for the BSE signal by use of digital image processing has been proposed. This method is called the linearization of the η =f(Z) characteristic. The function approximating the experimental η =f (Z) dependence was determined by numerical methods. After characteristics linearization, the digital image in COMPO mode allows to distinguish between two elements with high atomic numbers if their atomic numbers differ by ΔZ = 1.
High‐resolution field‐emission scanning electron microscopy of nuclear pore complex
Authors: Ris Hans 
Published: June 2010

AbstractThe nuclear pore complex (NPC) is a large macro‐molecular assembly inserted into the nuclear envelope (NE). It controls the traffic of proteins, RNA, and RNA proteins between nucleus and cytoplasm. Its chemical composition and function are now intensively investigated in many organisms. To understand this unique membrane transport system, we must know the supramolecular organization of the NPC. In recent years, high‐resolution field‐emission scanning electron microscopy has made important contributions to our knowledge of NPC structure. It provided the first images of the complex and beautiful fish trap‐like structure of its intranuclear surface, documented in this review. It also has provided the first images of a new intranuclear structure, a system of branching hollow cables connecting the nuclear interior with the NPCs at the nuclear surface. Most likely this is an intranuclear transport system, assuring efficient exchange between the nuclear interior and the NE, especially in large nuclei.
Choosing the optimum accelerating voltage (EO) to visualize submicron precipitates with a field emission scanning electron microscope
Authors: Hovington Pierre , Gauvin Raynald , Drouin Dominique 
Published: June 2010

AbstractWith the advent of field emission scanning electron microscopes (FESEM), the observation of small phases in the 5 to 50 nm range seems to be possible at low accelerating voltage using backscattered electron imaging mode. In this context, it is important to understand the contrast of multiphased materials at such low energy. A Monte Carlo program to simulate electron trajectories of multiphased materials (CASINO) was used to compute electron backscattering images. Simulations of images for various compositions of spherical precipitates embedded in a homogeneous matrix as a function of precipitate size and accelerating voltage are presented. These simulations show the concept of an optimum accelerating voltage to maximize the contrast of electron backscattering images. The results presented in this paper show that the contrast of backscattering images of multiphased images in the scanning electron microscope is not only a function of the atomic number difference, but that it is also strongly related to the geometry and the size of the phases.
Comparative characterization of chemical vapor deposition diamond films by scanning cathodoluminescence microscopy
Authors: Obraztsov A. N. , Saparin G. V. , Obyden S. K. , Pavlovsky I. Y. 
Published: June 2010

AbstractThin diamond films grown by chemical vapor deposition (CVD) process on Si substrates under similar deposition conditions in the microwave‐excited (MW) and direct current (DC) plasma discharges were taken for comparative examination. Raman spectra, photoluminescence (PL) spectroscopy, and color cathodoluminescence scanning electron microscopy (CCL‐SEM) have been used for characterization of the structure and composition features of poly‐crystalline diamond films. No essential difference in Raman spectra for the CVD diamond films was detected. A significant difference was revealed in the PL spectra and in CCL‐SEM images.
A new method of scanning tunneling spectroscopy for study of the energy structure of semiconductors and free electron gas in metals
Authors: Pavlov A. , Ihantola H. 
Published: June 2010

AbstractIn this study, anew method for the scanning tunneling spectroscopy (STS) of direct and indirect gap semiconductors and free electron gas in metals is proposed. Band structures of Si, porous Si, and Ge were studied. The tunneling current‐voltage characteristics of Si and porous Si surfaces were measured over different voltage intervals from tens of mV to 20 V under incident light from an Xe lamp and those of a Ge surface in the dark. The correlation between the shapes of the I‐V curves and band structure of the materials was calculated. It was found that the curves are linear if measured in the voltage range V0Eg/(2e) and nonlinear when V0α Eg/(2e) (in the measurements the applied voltage was changed from ‐V0to V0). The method was used for the observation of a new effect of tunneling of free electron gas having thermal energies from a metal tip to a band gap state of the semiconductor. The energy spectrum of free electron gas was measured.
Calculation of concentration depth profiles in electron probe microanalysis
Authors: Andrae Michael , Röhrbacher Kurt , Klein Peter , Udvary Leonhard , Wernisch Johann 
Published: June 2010

AbstractBased on a multiple reflection model, the concentration depth profiles of gold diffused into a silver substrate are determined. To conclude the structure of the sample from the measured intensity of radiation, an accurate correction procedure is necessary. A new model was developed for this purpose. Since the new electron probe microanalysis (EPMA) correction procedure is also valid for tilted samples, measurements with different geometries could be performed. The different angles of incidence and take‐off angles allow for a better comparison of theory with experiment. One advantage of the applied multiple reflection model is that it can be extended comparatively easily with the analysis of layered specimens. Measurements of some specimens with one layer on a substrate are reported. The mean deviation of calculated thicknesses is about 10%. To calculate depth profiles, gold was evaporated with physical vapor deposition on silver foils. The thicknesses of evaporated gold films were 50 and 100 nm. Then the specimens were annealed at a temperature of approximately 400°C. Finally, the concentration depth profiles were quantified with EPMA. The shape of the profiles was derived from a simple diffusion model valid for the samples under consideration. To check the shape of the functions obtained, a comparison with measurements by secondary ion mass spectrometry was performed.
Development of high‐resolution field emission scanning electron microscopy with multifunctions for chargeless observation of nonconducting surface
Authors: Yamamoto Youiti , Yamada Mitsuru , Negishi Tsutomu 
Published: June 2010

AbstractWe have developed a fully digital field emission scanning electron microscope (FE‐SEM) with multifunctions to compensate the charging up of nonconducting surfaces. High‐voltage observation, minimum electron dose, variable scanning speed, averaging, integration, tuning of surface potential, and cyclotron movements of secondary electrons have been achieved. This FE‐SEM was successfully applied to observe resist, diatomaceous earth, aluminum oxide, and zeolite surfaces. The accelerating voltage is changeable in a range from 0.5 to 30 kV, and the probe current on the sample can be varied from 2×10‐9 to l×10‐13A to supply optimum electron dose. By using a snorkel‐ type, strongly excited objective lens (OL) immersing the samples in the magnetic field, the secondary electrons are extracted from the sample. For guiding electrons into the built‐in lens‐type secondary electron detector (SED), newly developed accelerating and retarding electrodes are installed in the OL to tune the surface potential. Furthermore, this FE‐SEM can select 10 scan speeds, and the averaging and integration of secondary electron image signals are possible under every selected scan speed.
Recent case histories of food product ‐metal container interactions using scanning electron microscopy‐x‐ray microanalysis
Authors: Charbonneau James E. 
Published: June 2010

AbstractScanning electron microscopy (SEM) and x‐ray microanalysis (EDS) were used to investigate stress corrosion cracking (SCC) in plain tinplate food cans, product discoloration, filiform corrosion, pitting/perforation corrosion, and loss of coating adhesion in enameled food cans. Intergranular SCC of uncoated tinplate occurred in canned pineapple juice. This is a rare occurrence in acid food products. The fracture developed in the can headspace only at the product line/metal interface by an interaction of the detinned metal surface with stress‐inducing compounds in the product. Black discoloration of rice granules in the can headspace of a chicken and rice product was caused by the formation of metal sulfides. The source of the metal contamination was traced to metallic dirt in the coating on the tin‐free steel end. Blackening of light tan‐colored olives and brine occurred after 1 year of storage in enameled tinplate containers as aresult of pitting corrosion at the side seam weld. The cause of the pitting was a defective side seam stripe which failed to protect the weld. A perforation problem occurred at the score line of aluminum‐tinplate bimetallic cans. The failure was caused by the high chloride content of the fruit product. Filiform corrosion resulted in perforations that occurred on the outside surfaces of two‐piece tin‐free steel cans packed with tuna. The cause of the corrosion was related to scratch defects in the exterior coating and the presence of chloride and sulfate cannery residues in the corroded areas. An enamel adhesion failure developed inside two‐piece tin‐free steel cans that contained mushrooms. Wrinkles in the coating which were introduced during can manufacture were cracked. The fractures were pathways for product‐steel interaction which resulted in container failure.
Three‐dimensional localisation of fluorescence resonance energy transfer in living cells under two‐photon excitation
Authors: Xu Ming G. , Crimeen Blessing , Ludford‐Menting Mandy J. , Gan Xiaosong , Russell Sarah M. , Gu Min 
Published: June 2010

AbstractThree‐dimensional (3‐D) imaging of fluorescence resonance energy transfer (FRET) in human cells under two‐photon excitation was demonstrated in this study. A sample was prepared by expressing a donor and an acceptor in living cells and using an antibody to secure the proximity of contact between the donor and the acceptor. The quenching of fluorescence emission of a donor in the double‐labelled cells indicates the presence of FRET that occurred in these living cells. Because of the quadratic relation of the excitation power, 3‐D localisation of FRET becomes possible.
Scanning electron microscopy of nonconductive specimens at critical energies in a cathode lens system
Authors: Frank Luděk , Zadražil Martin , Müllerová Ilona 
Published: June 2010

AbstractA method for scanning electron microscopy imaging of nonconductive specimens, based on measurement and utilisation of a critical energy, is described in detail together with examples of its application. The critical energy, at which the total electron yield curve crosses the unit level, is estimated on the basis of measurement of the image signal development from the beginning of irradiation. This approach, concentrated onto the detected signal as the only quantity crucial for the given purpose of acquiring a noncharged micrograph, evades consequences of any changes in an irradiated specimen that influence the total electron yield curve and possibly also the critical energy value. Implementation of the automated method, realised using a cathode lens‐equipped scanning electron microsope (SEM), enables one to establish a mean rate of charging over the field of view and its dependence on the electron landing energy. This dependence enables one to determine the energy of a minimum damage of the image of the given field of view. Factors influencing reliability and applicability of the method are discussed and examples of noncharged micrographs of specimens from both life and material science fields are presented.