Detection and Localization of Eu on Biosilica by Analytical Scanning Electron Microscopy

2021 ◽  
pp. 1-10
Author(s):  
Ellen Hieckmann ◽  
Kaitlin K. K. Kammerlander ◽  
Lydia Köhler ◽  
Laura Neumann ◽  
Stefan Saager ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Scattering ◽  
Contaminated Sites ◽  
Entire Surface ◽  
X Ray ◽  
Analytical Scanning Electron Microscopy ◽  
Thermogravimetric Studies ◽  
Detection And Localization ◽  
Scanning Electron ◽  
The Eu

Algae like diatoms are widely studied as a means to remediate anthropogenically contaminated sites. In the present study, CL (cathodoluminescence) and EDX (energy-dispersive X-ray) spectroscopy in an SEM (scanning electron microscope) were optimized for the detection of Eu(III) sorbed on diatom biosilica. The required stability of biosilica under a focused electron beam was extensively investigated. Using experimentally determined data of thermal properties, the temperature increase within biosilica exposed to an electron beam was simulated by finite element calculations based on results from Monte Carlo simulations of electron scattering. Complementary thermogravimetric studies substantiated a chemical stability of biosilica in a wide temperature range, confirming its suitability for long-lasting SEM investigations. In subsequent EDX measurements, characteristic Eu lines were detected. Eu was found to preferentially accumulate and aggregate on silica fragments. CL spectra were obtained for the Eu(III) reference material, EuCl3. For Eu-loaded biosilica, even parts without detectable Eu signal in the EDX spectra show significant Eu(III) signals in the CL spectra. This highlights the sensitivity of CL in studying f-element sorption. CL data showed that Eu(III) was distributed on the entire surface. In conclusion, this work demonstrates the merit of CL and EDX methods for sorption studies on biogenic materials.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

scholarly journals Investigations of M3Al8O15:Eu3+,Dy3+ (M = Ba, Ca, Mg) phosphors

2016 ◽  
Vol 34 (2) ◽  
pp. 412-417
Author(s):  
Esra Öztürk
Keyword(s):  
Electron Microscopy ◽  
Solid State Reaction Method ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Three Samples ◽  
Scanning Electron ◽  
The Eu

AbstractIn this work, aluminate type phosphorescence materials were synthesized via the solid state reaction method and the photoluminescence (PL) properties, including excitation and emission bands, were investigated considering the effect of trace amounts of activator (Eu3+) and co-activator (Dy3+). The estimated thermal behavior of the samples at certain temperatures (> 1000 °C) during heat treatment was characterized by differential thermal analysis (DTA) and thermogravimetry (TG). The possible phase formation was characterized by X-ray diffraction (XRD). The morphological characterization of the samples was performed by scanning electron microscopy (SEM). The PL analysis of three samples showed maximum emission bands at around 610 nm, and additionally near 589 nm, 648 nm and 695 nm. The bands were attributed to typical transitions of the Eu3+ ions.

X-Ray Energy Dispersive Spectroscopy in the Environmental Scanning Electron Microscope

1998 ◽  
Vol 4 (S2) ◽  
pp. 182-183
Author(s):  
John F. Mansfield ◽  
Brett L. Pennington
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive Spectroscopy ◽  
Primary Electron ◽  
Environmental Scanning ◽  
Primary Electron Beam ◽  
X Ray ◽  
Environmental Sem ◽  
Scanning Electron

The environmental scanning electron microscope (Environmental SEM) has proved to be a powerful tool in both materials science and the life sciences. Full characterization of materials in the environmental SEM often requires chemical analysis by X-ray energy dispersive spectroscopy (XEDS). However, the spatial resolution of the XEDS signal can be severely degraded by the gaseous environment in the sample chamber. At an operating pressure of 5Torr a significant fraction of the primary electron beam is scattered after it passes through the final pressure limiting aperture and before it strikes the sample. Bolon and Griffin have both published data that illustrates this effect very well. Bolon revealed that 45% of the primary electron beam was scattered by more than 25 μm in an Environmental SEM operating at an accelerating voltage of 30kV, with a water vapor pressure of 3Torr and a working distance of 15mm.

Microstructure Analysis of Electron-Beam Brazed γ-Titanium Aluminide

2011 ◽  
Vol 690 ◽  
pp. 153-156
Author(s):  
Uwe Reisgen ◽  
Simon Olschok ◽  
Alexander Backhaus
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Beam ◽  
Titanium Aluminide ◽  
Titanium Aluminides ◽  
Microstructure Analysis ◽  
Energy Dispersive ◽  
X Ray ◽  
Scanning Electron

This paper gives an account of research which has been carried out on electron-beam brazed specimens made of high-Niobium γ-titanium aluminides. The microstructure in the brazing area of two different brazes (TiCuNi and Ni 102) is explained and analysed via scanning electron microscopy and energy dispersive X-ray spectroscopy.

scholarly journals Membran Reaktor untuk Pembuatan dan Pemurnian Isomer Xylene

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Wahyudin Wahyudin ◽  
Hens Saputra
Keyword(s):  
Pore Size Distribution ◽  
Zeolite Membrane ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Alumina Catalyst ◽  
Mfi Zeolite ◽  
Entire Surface ◽  
X Ray ◽  
Silica Alumina ◽  
Scanning Electron

Abstrak Membran reaktor merupakan konsep perpaduan dari sistem reaksi dan proses pemisahan/pemurnian. Membran ini disebut juga sebagai membran katalis atau sistem katalis-membran. Dengan membran reaktor ini diharapkan konversi suatu reaksi dapat ditingkatkan dan diperoleh suatu produk yang memiliki tingkat kemurnian lebih tinggi. Sebagai katalis digunakan silica alumina yang berukuran 1,0 mm. Membran anorganik  zeolit MFI dilapiskan menutupi seluruh permukaan katalis. Bahan baku yang digunakan antara lain tetraethylortosilicate (TEOS) sebagai sumber silikat dan template organik tetraprophyl ammonium bromide (TPABr). Proses kristalisasi dilakukan pada temperatur 453 K di dalam autogeneous autoclave, dilanjutkan dengan kalsinasi pada temperatur 873 K selama 1 jam. Karakterisasi membran zeolit yang dihasilkan dilakukan dengan X-ray diffraction (XRD) dan pengamatan dengan Scanning Electron Mycroscope (SEM). Karakteristik pori dipelajari menggunakan metode physisorption dan BJH pore size distribution. Selain itu dilakukan pula uji selektifitas dan alkilasi toluena dan xylene. Berdasarkan pengamatan menggunakan XRD mengindikasikan adanya struktur zeolit MFI pada sampel membrane katalis yang dihasilkan. Diperkuat dengan obserbasi SEM menunjukkan bahwa membran zeolit MFI melapisi seluruh permukaan pelet silika alumina dan terdapat indikasi terjadinya komposit terhadap silika alumina pada daerah perbatasan antara membran zeolit atau lapisan bagian luar dengan katalis silika alumina. Hasil pengujian menunjukkan hasil bahwa membran reaktor zeolit MFI berpotensi untuk diaplikasikan sebagai membran katalis yang bersifat sangat selektif terhadap bentuk suatu molekul. Kata kunci: membran reaktor, isomer, xylene, zeolit, silika alumina, hidrotermal   Abstract Membrane fusion reactor is the concept of system reactions and separation processes of purification. These membranes are called also catalyst membrane or catalyst-membrane system. With the reactor membrane is expected conversion of a reaction can be increased and obtained a product having a higher purity. As the silica alumina catalyst used measuring 1.0 mm. MFI zeolite coated inorganic membranes covering the entire surface of the catalyst. The raw materials used include tetraethylortosilicate (TEOS) as the source of silicates and organic template tetrapropyl ammonium bromide (TPABr). Crystallization process carried out at a temperature of 453 K in the autogeneous autoclave, followed by calcination at a temperature of 873 K for 1 hour. Characterization of zeolite membranes produced performed by X-ray diffraction (XRD) and scanning electron observations with Mycroscope (SEM). Pore ​​characteristics were studied using physisorption method and BJH pore size distribution. In addition, the selectivity of the test is also conducted and alkylation of toluene and xylene. Based on observations using XRD indicates a structure of MFI zeolite membrane on the resulting catalyst samples. Reinforced with SEM showed that the MFI zeolite membrane coating the entire surface of the silica alumina pellets and there are indications of the silica alumina composites in the border area between zeolite membrane or outer coating with silica alumina catalyst. The results show that the results of MFI zeolite reactor  membrane has the potential to be applied as a catalyst membrane that is highly selective to form a molecule. Keywords : reactor membrane, isomers, xylene, zeolite, silica alumina, hydrothermal

Identification of Several New Ferromagnetic and Antiferromagnetic Rare Earth Cuprates

1990 ◽  
Vol 48 (2) ◽  
pp. 498-499
Author(s):  
M. Fendorf ◽  
S.W. Keller ◽  
A.M. Stacy ◽  
R. Gronsky
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rare Earth ◽  
Magnetic Behavior ◽  
Chemical Form ◽  
The Other ◽  
X Ray ◽  
Scanning Electron ◽  
The Eu

Several new rare earth cuprates having the chemical form RxCuyOz (where R represents the rare earths La, Nd, Sm, Eu, and Gd) have recently been synthesized using a NaOH flux at 400°C. The materials are polycrystalline, and contain varying amounts of R2CuO4 and CuO. During subsequent susceptibility measurements using a SQUID magnetometer, it was found that the Gd material orders antiferromagnetically at approximately 14K, while the other compounds become ferromagnetic between 18K and 28K. Treatment of the powders with 12M HC1 for several minutes dissolves the impurity R2CuO4 and CuO phases, thus facilitating efforts to determine the composition and crystal structure of the new ferromagnetic and antiferromagnetic cuprates. Details of synthesis and magnetic behavior of these materials are to be published elsewhere. In this study, a first attempt is made to characterize the Eu and Gd materials.Energy dispersive x-ray analysis carried out during scanning electron microscopy work indicates that the R:Cu ratio in the Gd material is 1:1.70 (close to 3:5) and that in the Eu material is 1:1.96 (close to 1:2).

The effect of high-current pulsed electron beam modification on the surface wetting property of polyamide 6

e-Polymers ◽  
2017 ◽  
Vol 17 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Yuan Fang Chen ◽  
Tao Zhang ◽  
Meng Tang ◽  
Ding Xie ◽  
Qian Long ◽  
...  
Keyword(s):  
Electron Beam ◽  
Photoelectron Spectroscopy ◽  
Polyamide 6 ◽  
High Current ◽  
Surface Wetting ◽  
Water Contact ◽  
X Ray ◽  
Pulsed Electron Beam ◽  
Wetting Property ◽  
Scanning Electron

AbstractThis study demonstrates that different modification pulse voltages affect the wetting property of the surface of polyamide 6 (PA6) with a certain regularity. Broadly, the hydrophilic property of PA6’s surface increases with increasing pulsed voltage. Based on scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis, this paper discusses the mechanism by which high current pulsed electron beam (HCPEB) etching modification influences the surface wettability of PA6. Within a certain range below 28 kV, this effect is caused by an increase of in surface roughness due to HCPEB bombardment of the surface. Within a certain range above 28 kV, HCPEB changes the surface morphology, resulting in changes to the wetting property. Furthermore, by using various pulsed voltages to modify the PA6 surface, this study investigated the ability of the Wenzel model to explain changes in the water contact angle and wetting property of PA6’s surface.

Alteration Minerals in Granitic Rock at Ashio as Radionuclide Adsorption Materials

1994 ◽  
Vol 353 ◽  
Author(s):  
S. Hamasaki ◽  
K. Tsukimura ◽  
K. Fujimoto ◽  
K. Omura ◽  
R. Ikeda
Keyword(s):  
Host Rock ◽  
Mineral Assemblage ◽  
Granitic Rock ◽  
Drill Core ◽  
Radionuclide Transport ◽  
Central Japan ◽  
X Ray ◽  
Alteration Minerals ◽  
Analytical Scanning Electron Microscopy ◽  
Scanning Electron

AbstractAlteration minerals from a drill-core (maximum depth 2002 m) in the granitic rock at Ashio, central Japan, were studied by optical microscopy, X-ray diffractometry and analytical scanning electron microscopy. In the host rock, biotite is altered to chlorite and plagioclase to illite. Calcite has precipitated in veinlets and grain boundaries. The host rock close to fractures is strongly altered, whereas the rocks distant from fractures are less altered. Quartz, illite, chlorite, laumontite and calcite have precipitated on fracture walls. The alteration minerals are estimated to have formed in the range 140–200°C, higher than the present temperature (13°96°C). The chemical composition of the ground water in the granitic rock at Ashio was estimated thermodynamically from the mineral assemblage. The alteration reaction of palgioclase and the precipitation of calcite may occur simultaneously. The alteration minerals formed in the host rock and in the fractures may adsorb radionuclides effectively, and thus may inhibit radionuclide transport to biosphere.

From the Scanning Electron Microscope to the Scanning Electron Macroscope with X-Ray Microanalysis in the ESEM

2000 ◽  
Vol 6 (S2) ◽  
pp. 792-793 ◽  
Author(s):  
Raynald Gauvin
Keyword(s):  
Monte Carlo ◽  
Electron Beam ◽  
Electron Microscope ◽  
Incident Beam ◽  
Correction Procedure ◽  
Measured Intensity ◽  
X Ray ◽  
Image Position ◽  
Corrected Intensity ◽  
Scanning Electron

Recently, a new correction procedure has been proposed in order to perform X-Ray microanalysis in the ESEM or in the VP-SEM1. This new correction procedure is based on this equation:where I is the measured intensity at a given pressure P, Ip is the intensity that would be generated without any gas in the microscope (the corrected intensity) and Im is the intensity with complete scattering of the electron beam. Im is therefore the contribution of the skirt on I. In equation (1), fp is the fraction of the incident beam, which is not scattered by the gas above the specimen, and it can be obtained from Monte Carlo simulations or from an analytical equation.

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