Electron Microscope-energy Dispersive X-ray Spectrometer Research Articles

TEM analysis of the interfacial defects in the superconducting GdBa2Cu3O7−δ tapes synthesized by IBAD-PLD

A cross-sectional transmission electron microscope (TEM) analysis was conducted on the GdBa2Cu3O7−δ (GdBCO) tapes, which were synthesized by depositing Al2O3/Gd2O3/IBAD–MgO/epi-MgO buffer layers on the hastelloy substrate by the ion-beam-assisted deposition (IBAD) method and subsequently depositing LaMnO3 and GdBCO layer by pulsed laser deposition (PLD) method. The average critical current (Ic) value was 62.5A and the average full width at half maximum (FWHM) values of the in-plane GdBCO(102) was 4.4°. The thickness of the each stacked layer was precisely measured with TEM micrographs and the structural features were analyzed with scanning transmission electron microscope-energy dispersive X-ray spectrometer (STEM-EDS). The diffusion of the Cr ion in the hastelloy into the Al2O3 layer was detected and the thickness of the diffused layer was about 10nm.

A novel pH-sensitive hydrogel composed of N, O-carboxymethyl chitosan and alginate cross-linked by genipin for protein drug delivery

A novel pH-sensitive hydrogel system composed of a water-soluble chitosan derivative ( N, O-carboxymethyl chitosan, NOCC) and alginate blended with genipin was developed for controlling protein drug delivery. Genipin, a naturally occurring cross-linking agent, is significantly less cytotoxic than glutaraldehyde and may provide a less extent of cross-linking to form a semiinterpenetrating polymeric network (semi-IPN) within the developed hydrogel system. The drug-loading process used in the study was simple and mild. All procedures used were performed in aqueous medium at neutral environment. In the study, preparation of the NOCC/alginate-based hydrogels was reported. Swelling characteristics of these hydrogels as a function of pH values were investigated. Additionally, release profiles of a model protein drug (bovine serum albumin, BSA) from test hydrogels were studied in simulated gastric and intestinal media. The semi-IPN formation of the genipin-cross-linked NOCC/alginate hydrogel was confirmed by means of the scanning electron microscopy-energy dispersive X-ray spectrometer (SEM-EDS) and the ninhydrin assays. The percentage of decrease of free amino groups and cross-linking density for the NOCC/alginate hydrogel cross-linked with 0.75 mM genipin were 18% and 26 mol/m 3, respectively. At pH 1.2, the swelling ratio of the genipin-cross-linked NOCC/alginate hydrogel was limited (2.5) due to formation of hydrogen bonds between NOCC and alginate. At pH 7.4, the carboxylic acid groups on the genipin-cross-linked NOCC/alginate hydrogel became progressively ionized. In this case, the hydrogel swelled more significantly (6.5) due to a large swelling force created by the electrostatic repulsion between the ionized acid groups. The amount of BSA released at pH 1.2 was relatively low (20%), while that released at pH 7.4 increased significantly (80%). The results clearly suggested that the genipin-cross-linked NOCC/alginate hydrogel could be a suitable polymeric carrier for site-specific protein drug delivery in the intestine.

Nondestructive Depth Profiling by Specimen Tilting Using Scanning Electron Microscope-Energy Dispersive X-Ray Spectrometer

In order to perform nondestructive depth profiling, a glancing incidence method has been attempted by specimen tilting using a scanning electron microscope-energy dispersive X-ray spectrometer. Two-dimensional (2D) compositional mapping was carried out using double/triple-layered specimens at various tilt angles, namely glancing incidence angles. It was confirmed that the visibility of the compositional map clearly varied depending on the incidence angle and the depth distribution. The X-ray intensity dependence on the incidence angle at each observation point is obtained from a series of compositional maps and that enables qualitative 2D depth profiling of spatial resolution in the micrometer range and depth resolution of a few tens of nm.

Progress of Scanning Electron Microscopy (SEM) and Electron Probe Microanalysis (EPMA) for Pulp and Paper Specimens

In previous paper, the development of EPMA color mapping technique in application to pulp and paper specimen was described. In this paper, several examples of color mapping applied to pulp and paper specimens were demonstrated.Distribution of fillers, pigments, binder (latex and casein), silicone, phenolic resin, lignin and xylan in the cross sections were exhibited. Average profiles of the elements along thethickness direction in papers were shown corresponding to the color maps.The element tagging techniques were utilized to monitor organic substances which needed to tag with some easily detectable metal iron. It was found that Os tagged latex, casein, phenolic resin and lignin. It was also confirmed that lignin was tagged with either Br or Hg and xylan with Fe.In the usual analysis by EPMA with STE (Stearate) as X-ray dispersive crystal, it was very difficult to analyze nitrogen in such specimen as paper because the concentration of carbon is extremely higher than that of nitrogen. We tried to use a new Layered Dispersive Element (LDE) instead of STE for the analysis of nitrogen (casein) in coated paper and found that the measurement of casein distribution in cross section of coated paper was possible with this procedure.STEM-EDS (Scanning Transmission Electron Microscope-Energy Dispersive X-ray Spectrometer) proved very useful to measure the distribution of elements more precisely at higher magnification by using thin cross section of specimen.

Evaluating Visual Criteria for Identifying Carbon- and Iron-Based Pottery Paints from the Four Corners Region Using SEM-EDS

AbstractPaint types on black-on-white pottery in the prehistoric American Southwest have had significance for both chronological and sociocultural interpretations. Visual attributes have formed the basis for distinguishing carbon- and mineral-based paints on ancient black-on-white pottery in the American Southwest for over 60 years. In this study, an SEM-EDS (scanning electron microscope-energy dispersive X-ray spectrometer) system was first used to make an independent objective determination of the mineral or non-mineral paint present on 15 Mesa Verde White Ware sherds. Then, a group of 19 people (including experienced archaeologists and newly trained individuals) examined and classified the paint on these sherds, achieving an overall accuracy of 84.2 percent. This group also ranked in priority order the visual attributes they felt were most useful in determining pottery paint type: nature of edges (fuzzy, sharp), absorption (soaks in, sits on top), luster (shiny, dull), color range (black-gray-blue; black-brown-reddish), flakiness (doesn't flake off, flakes off), thickness (thin, thick), and surface polish (polish striations visible through paint, striations not visible through paint). In each case, the attribute applicable to carbon-based paint is listed first. The most difficult sherds for the group to identify displayed attributes of both carbon and mineral paints. A category for "mixed" paint type, already in use by archaeologists, is a reasonable third category for labeling sherd paint, as long as it does not become a "catch-all" category. For problematic sherds, the SEM-EDS can be used to characterize paint type, then the visual attributes adjusted to improve investigator accuracy in paint type determination.

ＥＰＭＡによる木材及びパルプ中のリグニン分布状態測定法の検討 （第２報） アカシヤ材チップ及びＫＰ蒸解粕中のリグニン分布状態の観察

The observation of lignin distribution in the cross section of Acacia chips and the digester rejects in kraft pulping was carried out by using EPMA (Electron Probe Microanalyzer) with the newly developed procedure of Osmium-tagging to lignin, presented in the previous report. The distribution pattern of lignin can be detected clearly by the distribution and concentration of the Osmium tagged to lignin. STEM-EDS (Scanning Transmission Electron Microscope-Energy dispersive X-ray Spectrometer) technique was also applied to observe more precisely the distribution of the Os-tagged lignin in wood components. The observed results are summarised as follows ;(1) More vessels, which were thickly surrounded by vasicentric parenchyma cells, were observed in the cross section of the KP rejects than in that of the chips.(2) It was found that the lignin concentration is high in these vasicentric parenchyma cells for the KP rejects and on the other hand it is high in ray parenchyma cells for the normal chips. High Osmium concentration in parenchyma cells may be thought to depends not only lignin but on resinous substances which can not be extracted with alcohol benzene.(3) STEM-EDS analysis revealed that in the KP rejects fiber cell walls are considerably deformed and delignified but firmly combined with lignin rich middle lamella.(4) The distribution of the lignin in the cross section of the KP reject resembled that of the chips near the knots. Accordingly, it is considered that the difficulty of digesting of chips much depend on the distribution of lignin in the chips.

Effect of additives on the microstructure and mechanical properties of commercial alumina ceramics

The effect of impurities or additives on the microstructure of some commercial alumina ceramic samples have been characterized by scanning electron microscope-energy dispersive x-ray spectrometer and the mechanical properties investigated. Both the hardness and the toughness have been found to increase as the SiO 2 content decreases, and the theoretical density is reached in these materials. Grain size and distribution seem to be important factors in the mechanical properties of alumina ceramics. If the additives are controlled carefully, finer grain size and distribution can be obtained, together with a high relative density in terms of pore distribution characteristics and consequently enhanced mechanical properties.

Discussion of the paper “identification of hydrated cement constituents using a scanning electron microscope-energy dispersive X-ray spectrometer combination” by Sidney Diamond

Discussion of the paper “identification of hydrated cement constituents using a scanning electron microscope-energy dispersive X-ray spectrometer combination” by Sidney Diamond

A reply to F. Radjy's discussion on “identification of hydrated cement constituents using a scanning electron microscope-energy dispersive X-ray spectrometer combination”

A reply to F. Radjy's discussion on “identification of hydrated cement constituents using a scanning electron microscope-energy dispersive X-ray spectrometer combination”

Identification of hydrated cement constituents using a scanning electron microscope energy dispersive X-ray spectrometer combination

Preliminary studies of the chemical composition of individual particles and local areas in hydrated cement pastes were carried out using a scanning electron microscope-energy dispersive x-ray spectrometer combination. Calibration curves prepared from a series of homogeneous cement and hydrated cement compounds were used, the analysis being carried out in terms of ratios of calcium oxide to silicon, sulfur, and aluminum oxides. Sulfur was distributed throughout the calcium silicate hydrate gel, except for regions thought to represent “inner” hydration product. Apparent mole ratios of calcium oxide to silica ranged generally between 2 and 3, considerably higher than had been expected. Various morphological features were interpreted in the light of their chemical compositions.