bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing the versatility of an EMscope SP2000A sputter cryo system on a Hitachi S‐570 scanning electron microscope
Authors: Wergin W. P. , Erbe E. F. 
Published: August 2011

AbstractThe EMscope SP2000A Sputter Cryo System provides biologists with a quick and reproducible procedure to freeze, fracture, etch, and sputter coat biological samples, which are then transferred to a cold stage for scanning electron microscopic (SEM) observations. The standard specimen holder, which is supplied with the unit and referred to as a “stub,” will accommodate most specimens; however, fabricating a variety of additional holders to perform more specialized functions considerably increases the versatility of the cryounit and the resolution that can be achieved. For example, the adaptation of small hinged or hingeless gold holders, which are used in the freeze‐fracture technique, produces clean fractures, allows for storage of samples in liquid nitrogen and permits samples to be frozen much more rapidly than the large standard holder. A short working distance holder has been designed, which allows samples to be inserted into the final objective lens, thereby resulting in a negative working distance up to −3 mm. Use of this holder with the upper detector in the Hitachi S‐570 SEM, enhances the secondary electron signal and thereby increases resolution of frozen samples severalfold. Another specimen holder has been designed, which allows conventional SEM stubs to be observed without removal of the cryostage. This modification permits use of the EMscope stage and specimen transfer device at room temperature without any further alteration or adjustment. These and other types of modified holders allow investigators to store, manipulate, fracture, and observe biological samples at resolutions not normally attainable with a standard SEM cryostage.
The utility of an on‐line digital image recording system for SEM
Authors: Oho E. , Kanaya K. 
Published: August 2011

AbstractAn on‐line digital image processing system provides several useful functions to SEM users. It is especially convenient for general SEM image storing and filing, preferable to conventional methods using video monitor, camera, and film. When equipped with state‐of‐the‐art magneto‐optical disk unit (external memory) and a video copy processor for printout of a digital SEM image, its usefulness is enhanced. In order to validate this useful function, we compare a modern on‐line digital image recording system with a conventional one, from the viewpoint of the general SEM user.
Characterization of polymer blends and block copolymers by conventional and low voltage SEM
Authors: Himelfarb P. B. , Labat K. B. 
Published: August 2011

AbstractMethods for characterizing block copolymers and polymer blends have been developed. Results from unstained and ruthenium tetroxide‐stained samples obtained by scanning electron microscopy at various acceleration voltage and by transmission electron microscopy are presented. The contrast in secondary images between components in stained polymer blends, where one component is preferentially stained, is maximized at higher acceleration voltage (10–25 keV). For measurement of particle size and shape, this is the preferred operating condition. To obtain high‐resolution images showing surface topography and fine structure, such as 20 nm domains in block copolymers, low‐voltage (<5 keV) imaging is preferred. Observation of the 20 nm domain structure in hydrogenated styrenebutadiene‐styrene shows that the spatial resolution now possible by scanning electron microscopy is comparable to that obtained by the traditional method of transmission electron microscopy.
Optimization of K‐ratio measurements for electron probe microanalysis
Authors: Schalkoord D. , Karduck P. , Rehbach W. P. 
Published: August 2011

AbstractElectron probe microanalysis (EPMA) has developed over the past 35 years into a versatile and reliable tool for the quantitative analysis of microregions in solids. Recently its applicability has been extended to the determination of the composition and the thickness of thin layers or multilayers on substrates. Precise and reliable quantifications by EPMA presuppose that the x‐ray intensities are measured under optimized conditions. We discuss some of the important aspects concerning the exact measurement of x‐ray intensities with signal properties. The topics covered range from size of the excitation volume and aspects of the generation, absorption, and emission of x‐rays to instrumental stability, optimization of instrumental parameters, and sources of errors in EPMA.
Cryoscanning electron microscopy of a layer of extracellular polysaccharides produced by bacterial colonies
Authors: Van Doorn W. G. , Thiel F. , Boekestein A. 
Published: August 2011

AbstractCryo‐SEM allowed observation of a layer of extracellular polysaccharides that covered colonies of the bacterium Pseudomonas aeruginosa, growing on agar substrate. The layer was not found when using conventional preparation techniques and scanning electron microscopy. It disappeared partially as a result of glutaraldehyde fixation, but mainly during alcohol dehydration and critical point drying.
Use of the scanning electron acoustic microscopy (SEAM) for the study OF III–V compound semiconductors
Authors: Bresse J.‐F. 
Published: August 2011

AbstractWe present here examples of applications of SEAM for the characterization of III‐V compound semiconductors and the visualisation of defects in devices. The electron acoustic signal can be quantitatively correlated to the total incorporation of impurities in electrically active or nonactive sites. Both act to reduce the lattice thermal conductivity and can be correlated to the appearance of complexes giving rise to deep‐level emission in cathodoluminescence. Introduction of impurities and lattice defects by ion implantation induces a reduction in thermal conductivity. The recovery of lattice disorder by thermal annealing can be estimated from the SEAM signal evolution. In devices, SEAM is a unique nondestructive method to visualise, with submicron spatial resolution, interface compound formation between an ohmic contact and the semiconductor or zones of nonadherence of a metallic overlayer to a semiconductor.
Investigation of urinary stones by colour cathodoluminescent scanning electron microscopy (CCL‐SEM)
Authors: Saparin G. V. , Obyden S. K. , Golovanov S. A. 
Published: August 2011

AbstractThe ability of colour cathodoluminescent SEM (CCL‐SEM) to detect chemical substances on the surface of urinary stones was demonstrated. CCL‐SEM combined with conventional scanning electron microscopy (SEM) provides more detailed characterization of the ultrastructure and chemical composition on the surface of urinary calculi. The technique enables the identification of functionally active zones for investigation of stone formation.
A semiautomated image analysis procedure for the quantification of dental microwear
Authors: Ungar P. S. , Simon J.‐C. , Cooper J. W. 
Published: August 2011

AbstractDifferent diets have been shown to leave characteristic patterns of microwear on the teeth of various mammalian species. The quantification of microwear features facilitates the comparison of taxa, and allows the discrimination of wear patterns associated with specific diets. The current study reports on a semiautomated image analysis procedure designed to expedite microwear quantification by engaging an IBM PS/2 running OS/2 Presentation Manager to compute and record the density, dimensions, and orientations of features defined by a user employing a mouse‐driven cursor. This technique is used to distinguish microwear patterns on the maxillary central incisors (I1s) of four Sumatran primate species (n=5 per taxon) with known dietary differences (Hylobates lar, Macaca fascicularis, Pongo pygmaeus, and Presbytis thomasi). However, although developed for a particular problem area, the analytical routines described are of general interest.
Electron‐count imaging in SEM
Authors: Yamada S. , Ito T. , Gouhara K. , Uchikawa Y. 
Published: August 2011

AbstractWe propose a method and a system for counting secondary electrons and for displaying micrographs from the SEM in real time. Evaluating the images obtained by the new system, we confirm that electron counting images have a higher signal to noise ratio than analogue images. This tendency is remarkable when the secondary electron signal is weak. We present the method and show experimental results obtained with our novel system for the detection of the secondary electron signal.
Calculation of the depth distribution function for continuous radiation
Authors: August H.‐J. , Wernisch J. 
Published: August 2011

AbstractA newly developed electron‐scattering model has been employed for calculating depth distribution functions for bremsstrahlung. A comparison with depth distribution functions used in connection with characteristic radiation reveals that the value of the surface radiation Φ(0) is comparatively smaller in cases of continuous radiation generation, while the centre of gravity of the bremsstrahlung curves is situated at larger mass depths, thus increasing the effect of radiation absorption phenomena. The discrepancies between both types of curves increase with decreases in atomic number and overvoltage ratio. In light of the present results the transformations of characteristic radiation curves for obtaining those for continuous radiation known so far are not likely to be physically realistic. Therefore, the principle of a new transformation is proposed.
Calculation of secondary electron production using a diffusion matrix
Authors: Czyżewski Z. , Joy D. C. 
Published: August 2011

AbstractThe diffusion matrix model proposed by Desai and Reimer (1990) has been investigated. After some modifications it appeared to be a powerful tool for rapid determination of the SE and BSE signals from two‐dimensional surface topographies. Results for low atomic number specimens show good agreement between experimental and theoretical data.
New method of cell membrane cholesterol marking for scanning electron microscopy
Authors: Povaliy T. M. , Popova E. G. , Gusev S. A. , Grigorieva M. E. , Zaitsev S. T. , Gritskova I. A. 
Published: August 2011

AbstractA new method is proposed for marking cell membrane cholesterol for SEM. The specific cholesterol markers (SCM) used consisted of polystyrene microspheres with digitonin on the surface. Digitonin is a specific cholesterol ligand. This method allows the investigation of the cholesterol content of phospholipid layers of the model and cell membranes. We analysed the distribution and quantity of cholesterol in model bilayer phospholipid membranes, liposomes, and in endothelial cell plasmalemma in health and during atherosclerosis.
A comparison of different intensity gradient formulae for orientation analysis of electron micrographs
Authors: Tovey N. K. , Martinez M. D. 
Published: August 2011

AbstractA detailed study of different intensity gradient formulae was conducted using 91 separate images covering a wide range of microfabric. It was found that a formula based on the 3 × 3 local pixel array gives almost identical results over all images with the standard formula based on 20 pixels forming a circular grouping within the 5 × 5 local array. Other formulae based on other groupings of pixels within the same pixel arrays give markedly different results. Computation times are reduced up to 45% when the 8,5 formula is used in place of the 20,14 one, and would thus seem to have advantages when large numbers of images are to be processed. While all formulae give somewhat similar domain‐segmented images when viewed visually, differences are noted both in the number of segmented domains as well as in the area of domains in each orientation sector. It is possible that the radius of the modal filter selected for the domain segmentation should be varied according to the formula type used.
Material analysis with cathodoluminescence standard spectra
Authors: Koschek G. , Lork A. 
Published: August 2011

AbstractThere are several cases where x‐ray analyses of material cannot yield the desired results (e.g., if materials of nearly identical chemical composition are considered.) Spectral cathodoluminescence (CL) investigations can be used to overcome these difficulties. For this purpose, CL standard spectra of different standard substances are presented here. The validity of these spectra is demonstrated by spectral analysis of a fireproof ceramic consisting of Al2O3 and of quartz and by an attempt to explain the origin of the CL properties of magmatic Zircon which is of significant importance in the field of geochronological investigations.
SEM‐CL studies of plastic deformation processes in crystals
Authors: Akchurin M. Sh. , Galstyan V. G. , Regel V. R. 
Published: August 2011

AbstractCathode luminescence investigation in the scanning electron microscope showed that, under a concentrated load, enormous stresses (near G) under the indenter relaxed due to the creation and movement of interstitials giving rise to structure reconstruction and the formation of an ultradispersed state. Such reconstruction is accompanied by significant changes in material stoichiomentry. The formation of a volume with nanocrystal structure affects microindentation activation energy. The formation and displacement of dislocations around the impression should be considered as a process secondary to stress relaxation, that is, as a result of the reorganization of material structure under the indenter tip described.
Fractal behaviour of electron scattering in solids
Authors: Gauvin Raynald , Drouin Dominique 
Published: August 2011

AbstractThe fractal behaviour of electron scattering in solids is studied with electron trajectories simulated by Monte Carlo simulations. More precisely, the box‐counting dimension of electron trajectories in C, Cu, Ag, and Au is determined. Then, the fractal dimension curve of the position of an electron in function of time simulated in a gold target shows that the first part of the electron trajectory is described by a persistent process and that the last part is described by random walk process. Finally, the multifractal behaviour of an electron trajectory simulated in gold is presented.
Cone‐beam reconstruction of plate‐like specimens
Authors: Wang G. , Lin T. H. , Cheng P. C. , Shinozaki D. M. 
Published: August 2011

AbstractAn x‐ray shadow projection microscope using a scannable point source of x‐rays is under development at AMIL‐ARTS, SUNY at Buffalo. Considering the characteristics of the x‐ray microscope of AMIL‐ARTS and the limitations of Feldkamp's cone‐beam reconstruction algorithm, a general cone‐beam image reconstruction algorithm has been developed. In x‐ray microscopy, many specimens are plate‐like. The reconstruction of a plate‐like specimen appears to be a limited angle problem. A novel method is presented to reconstruct a plate‐like specimen using the general cone‐beam reconstruction algorithm. Shepp and Logan's head phantom is used in validating this method. A method for synthesizing projection data of ellipsoids is described. Typical simulation results are given.
Investigation of nanoparticles by atomic and lateral force microscopy
Authors: Wurster R. , Ocker B. 
Published: August 2011

AbstractMetallic nanoparticles have been produced on vitreous carbon substrates by means of thermal evaporation. From pictures of the particles, made by a high‐resolution scanning electron microscope (HRSEM), a semispherical shape is suggested due to the total mass of deposited material. Atomic force microscopy (AFM) has been applied to this sample in order to get direct topographic information. The AFM has been operated with normal and super tips, the latter having a smaller cone angle and radius, thus following more precisely the contours of an object. Simultaneously lateral‐force microscopic (LFM) images have been recorded. Major differences between the contents of HRSEM‐ and AFM‐images are considered, emphasizing the important influence of the tips' geometry. Both the AFM and LFM line scans have been compared with and have qualitatively agreed with those calculated under simplifying assumptions.
Very low energy microscopy in commercial SEMs
Authors: Müllerová I. , Frank L. 
Published: August 2011

AbstractMinimum necessary adaptations are described that are sufficient for obtaining very low energy electron micrographs (VLEEMs) from commercially available routine scanning electron micrographs (SEMs) with the electrons accelerated to an energy of the order of tens of keV. A cathode lens inserted into the specimen chamber enables one to decelerate electrons in front of the specimen surface to a desired low landing energy, which can be freely varied even down to zero. When a potential slightly more negative than the accelerating voltage is applied, a scanning mirror electron microscopy mode can be effected. The achievable point resolution at very low energies proves to be not too dependent on the objective lens parameters, so that the physical limit of aberrations of the homogeneous field of the cathode lens is nearly attainable. The detection efficiency for the standard Everhart‐Thornley secondary electron detector is discussed, and results for the routine Tesla BS 340 SEM are presented.
The primary distribution of vacancies in the L‐shell after ionisation with electrons
Authors: Schiebl Christian , Wernisch Johann 
Published: August 2011

AbstractThe extraction of the relative distribution of the primary generated vacancies, which have been produced by ionisation with electrons, that is, the vacancy distribution prior to the appearance of Coster Kronig transitions, is presented for the L‐subshells. Only fundamental parameters such as fluorescence yields, Coster Kronig transition probabilities, and relative intensities were used for the derivation. Furthermore, a closer look is taken at the energy dependence of these relative primary vacancy distributions.
Direct STEM fabrication and characterization of self‐supporting carbon structures for nanoelectronics
Authors: Kislov N. A. 
Published: August 2011

AbstractA quantitative model is proposed to interpret the experimental results concerning the observed anomalous behavior of the thickness of growing self‐supporting carbon‐containing rods: a decrease in the thickness with increasing beam current. The model is based on the surface diffusion of hydrocarbon molecules and takes into account their ionization and desorption from the positively charged end of the growing rod. Possible causes of self‐maintained oscillation instability of the rod growth are discussed. Procedures are recommended to optimize the fabrication of self‐supporting carbon‐containing structures of complicated configurations and to reduce the negative effect of the incident beam electrons during their testing.
Characterisation of electronic and structural properties of thin silicon dioxide films by scanned probe microscopy
Authors: Welland M. E. , Murrell M. P. 
Published: August 2011

AbstractThis paper concerns the application of scanned probe microscopy to the study of thin silicon dioxide films. We show how the formation of 7 nm diameter silicon carbide particles on a silicon surface during high temperature processing affects the quality of subsequently grown oxide. To measure the local dielectric properties of thin oxides we have developed a new type of probe measurement which allows high resolution surface imaging, based on an atomic force microscope, combined with local electrical measurements. The spatial resolution of the electrical measurements was shown to be < 40 nm. Applying the technique to 500 nm capacitors fabricated on device quality oxide it was shown that some capacitors broke down during imaging while others remained stable at electric fields up to 30 MVcm−1. This higher breakdown strength may have substantial impact on future electronic device reliablity and performance.
Scanning probe microscopy for industrial applications: Selected examples
Authors: Dammer U. , Anselmetti D. , Dreier M. , Frommer J. , Fünfschilling J. , Gerth G. , Güntherodt H.‐J. , Haefke H. , Hidber H.‐R. , Howald L. , Hug H. J. , Jung T. H. , Lang H. P. , Lüthi R. , Meyer E. , Moser A. , Parashikov I. , Reimann P. , Richmond T. , Rüetschi M. , Rudin H. , Schwarz U. D. , Staufer U. , Sum R. 
Published: August 2011

AbstractSome examples are selected to demonstrate the variety of possible scanning probe microscopy application in industry. Magnetic and magneto‐optical storage media can be investigated by magnetic force microscopy, whereas a conventional scanning force microscope is used to examine surface features of many different materials, such as technical glasses, photosensitive materials, new superconductors, and biomolecules. Some other examples include the modification as well as the observation of liquid crystal devices, and the impact that scanning probe microscopy has on other techniques such as high precision stepping motors and high quality electron beam sources.
Recent advances in atomic force microscopy of DNA
Authors: Hansma Helen G. , Sinsheimer Robert L. , Groppe Jay , Bruice Thomas C. , Elings Virgil , Gurley Gus , Bezanilla Magdalena , Mastrangelo Iris A. , Hough Paul V. C. , Hansma Paul K. 
Published: August 2011

AbstractThree advances involving DNA in atomic force microscopy (AFM) are reported here. First a HEPES‐Mg buffer has been used that improves the spreading of DNA and provides good DNA coverage with as little as 200–500 picograms per sample. Second, the new “tapping” mode has been used to improve the ease and resolution of AFM‐imaging of DNA in air. Finally, AFM images are presented of single‐stranded ΦX‐174 virion DNA with the gene 32 single‐stranded binding protein. A summary of the current state of the field and of the methods for preparing and imaging DNA in the AFM is also presented.
Investigation of the formation of transition layers during LPE growth of GaAs
Authors: Bruk A. S. , Govorkov A. V. , Milvidskii M. G. , Popova E. V. , Shlenskii A. A. , Yugova T. G. 
Published: August 2011

AbstractThe properties of the near surface region in GaAs substrates doped with Sn and Te are studied after annealing in H2 flow or under controlled As overpressure. The transition regions between the bulk and the surface are formed upon such annealing. Also, the distribution of recombination centres across these transition regions is governed by defects diffused from the substrate and generated in the epitaxial layer.
Panchromatic cathodoluminescence characterization of III‐V lattice‐mismatched heterostructures
Authors: Salviati G. 
Published: August 2011

AbstractSome examples of the possibilities that panchromatic cathodoluminescence (PCL) offers in the scanning electron microscopy (SEM) characterization of III‐V semiconductors are presented. Investigations on lattice‐mismatched InGaAs/InP, InGaAs/ GaAs single heterostructures, and InGaAs/GaAs superlattices and GaAs/Ge and GaAs/InP single layers are shown. Further, the use of PCL as a support in the nondestructive determination of the sensitivity limit of Rutherford backscattering and x‐ray diffraction techniques in the study of strain release in some of the above mentioned heterostructures is presented. Finally, PCL on‐line study of dislocation movement induced by electron beam irradiation in the SEM, as evidence of InGaAs/GaAs superlattice metastability, is also presented.