Current Status of Solid-State X-Ray Systems

1985 ◽  
Vol 43 ◽  
pp. 158-161
Author(s):  
Martin Peckerar ◽  
Anastasios Tousimis
Keyword(s):  
Solid State ◽  
Electric Fields ◽  
Spectral Lines ◽  
Current Status ◽  
Mobile Charge ◽  
Electron Hole ◽  
X Ray ◽  
Sensing Systems ◽  
Transmission Electron ◽  
Electron Microscopes

Solid state x-ray sensing systems have been used for many years in conjunction with scanning and transmission electron microscopes. Such systems conveniently provide users with elemental area maps and quantitative chemical analyses of samples. Improvements on these tools are currently sought in the following areas: sensitivity at longer and shorter x-ray wavelengths and minimization of noise-broadening of spectral lines. In this paper, we review basic limitations and recent advances in each of these areas. Throughout the review, we emphasize the systems nature of the problem. That is. limitations exist not only in the sensor elements but also in the preamplifier/amplifier chain and in the interfaces between these components.Solid state x-ray sensors usually function by way of incident photons creating electron-hole pairs in semiconductor material. This radiation-produced mobile charge is swept into external circuitry by electric fields in the semiconductor bulk.

Semiconductor X-Ray Detection in the Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 130-131
Author(s):  
R. H. Duff ◽  
S. L. Bender
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
High Resolution ◽  
Gas Flow ◽  
X Ray ◽  
Solid State Detectors ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Conventional Transmission Electron Microscope

With the introduction of solid state detectors having resolutions of 300 eV or better, the feasibility of an efficient, nongeometry dependent X-ray detector of high resolution became a reality. The use of X-ray detecting systems in conjunction with electron microscopes has been limited to the dispersive type which is highly dependent on geometry or to the gas flow proportional counter which has poor resolution. Recently, high resolution solid state detectors have been used with scanning electron microscopes; however, no use has been made of them in the conventional transmission electron microscope. The usefulness of an elemental analysis together with morphological and crystallographic information is obvious.

Removing Substrate Background in TEM Microanalysis

1974 ◽  
Vol 32 ◽  
pp. 568-569
Author(s):  
John C. Russ ◽  
Nicholas C. Barbi
Keyword(s):  
Electrical Conductivity ◽  
Rapid Growth ◽  
Organic Film ◽  
Absolute Concentration ◽  
Background Signal ◽  
X Ray ◽  
Elemental Concentrations ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
The Continuum

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.

Transmission electron microscope studies in special ceramics

1978 ◽  
Vol 36 (1) ◽  
pp. 268-269
Author(s):  
A. Zangvil ◽  
L.J. Gauckler ◽  
G. Schneider ◽  
M. Rühle
Keyword(s):  
Phase Diagrams ◽  
Crystal Structures ◽  
Thin Foil ◽  
Limited Extent ◽  
Complex Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

CeO2/TiO2 Nanotubes Composites: Synthesis, Characterization, and Photocatalytic Properties

2012 ◽  
Vol 583 ◽  
pp. 86-90 ◽  
Author(s):  
Hai Bin Li ◽  
Xin Yong Li ◽  
Yan De Song ◽  
Shu Guang Chen ◽  
Ying Wang ◽  
...  
Keyword(s):  
Diffuse Reflectance Spectroscopy ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Electron Hole ◽  
Calcination Process ◽  
X Ray ◽  
Transmission Electron ◽  
Hole Recombination

TiO2nanotubes were prepared via a hydrothermal route. CeO2nanoparticles with diameters around 5nm were loaded onto the surface of TiO2nanotubes via a deposition approach followed by a calcination process. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-vis diffuse reflectance spectroscopy (UV-vis) were applied for the characterization of the as-prepared CeO2/TiO2nanotubes composites. The results show that CeO2particles are highly dispersed on the surface of TiO2nanotubes. The TiO2 nanotubes are modified to response to the visible light due to the combination with CeO2. The CeO2/TiO2nanotubes composites with a CeO2/TiO2atomic ratio of 2.5% show a further improvement on the photocatalytic activity for degradation of Rhodamine B in water. The presence of CeO2improves the light absorption of TiO2nanotubes and inhibits the electron-hole recombination.

scholarly journals Modern Microscopy on the Light Side: TEM in the Trenches

1993 ◽  
Vol 1 (4) ◽  
pp. 6-10
Author(s):  
Stephen E. Rice
Keyword(s):  
Science Fiction ◽  
Great Promise ◽  
Electron Holography ◽  
Imaging Device ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Light Side ◽  
Convergent Beam ◽  
Made In

Great strides have been made in the last decade in high resolution transmission electron microscopes (TEMs) which can also provide elemental information via energy dispersive X-ray analysis (EDX) or energy loss spectroscopy (EELS), and proponents of various TEM techniques make bold claims. Convergent beam elecjron diffraction and microdifff action shine as techniques for defect structure analysis and means for solving crystal structures. The spectroscopies can now be used to map chemical state information at a level which until recently might be encountered in science fiction. As a pure imaging device, electron holography holds great promise for providing Ehe ultimate (would you believe 0.1Å?) imaging resolution. Although conventional TEMs will never approach this, it appears that we are learning more and more about less and less, until we will soon know everything there is to know about nothing.

Preparation of PVC/Kaolin Nanocomposites through Solid State Shear Compounding Based on Pan-Milling

2011 ◽  
Vol 694 ◽  
pp. 350-354 ◽  
Author(s):  
Kan She Li ◽  
Ying Hong Chen ◽  
Hong Mei Niu ◽  
Jian Jun Chen
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Solid State ◽  
Impact Strength ◽  
Ambient Temperature ◽  
Mechanical Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Filled Composite

Solid state shear compounding technology (S3C) based on pan-milling is an effective method to prepare polymer/layered mineral composites with nano intercalating structure. The PVC/Kaolin compounding powders were successfully prepared by pan-milling at ambient temperature, and then the PVC/Kaolin nanocomposites were processed by moulding The structure and properties of PVC/Kaolin compounding powder and nanocomposites were investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and mechanical tests. The results showed that the mechanical properties of PVC/Kaolin nanocomposites prepared through S3C based on pan-milling 30 cycles at ambient temperature including elongation, tensile strength and notched impact strength were remarkably improved compared with conventional filled composites. The elongation of PVC / Kaolin nanocomposites with 4 %wt. Kaolin was 274.6%, which is 187.3 % higher than that for a conventional filled composite. The tensile strength was 54.0 MPa, which is 6.3 MPa higher than that for a conventional filled composite. The tensile strength of the nanocomposites with 8 %wt. Kaolin was 57.5 MPa, which is 9.1 MPa higher than that for a conventional filled composite. At the same time, the notched impact strength was 4.9 kJ/m2, which is 1.0 kJ/m2 higher than a conventional filled composite. Strengthening and toughening for PVC were synchronously realized. XRD, SEM and TEM verified that S3C based on pan-milling realized synchronously pulverizing, dispersion and compounding of PVC with kaolin Through 25-30 cycles pan-milling, PVC and Kaolin powders imbedded each other and made into uniform PVC/Kaolin compounding powders and nanocomposites. The strip flake of Kaolin particles with thickness less than 50 nanometer and the aspect ratio of 10 times dispersed homogeneously in the PVC matrix.

Aberration-corrected HRTEM of the Incommensurate Misfit Layer Compound (PbS)1.14NbS2

2007 ◽  
Vol 1026 ◽  
Author(s):  
Magnus Garbrecht ◽  
Erdmann Spiecker ◽  
Wolfgang Jäger ◽  
Karsten Tillmann
Keyword(s):  
Spherical Aberration ◽  
Atomic Scale ◽  
Transition Metal Dichalcogenide ◽  
Layer Compound ◽  
X Ray ◽  
Medium Voltage ◽  
Transmission Electron ◽  
Interesting Class ◽  
Electron Microscopes ◽  
Set Up

AbstractThe development of tunable spherical aberration (Cs) imaging correctors for medium-voltage transmission electron microscopes (TEM) offers new opportunities for atomic-scale in-vestigations of materials. A very interesting class of microstructures regarding a variety of dif-ferent physical properties are the transition metal dichalcogenide misfit layer compounds exhibit-ing a high density of incommensurate interfaces due to their stacked nature. In the present study, the benefits coming along with the set-up of negative CS imaging (NCSI) conditions (in TEM) are demonstrated by means of different examples regarding local inhomogeneities in (PbS)1.14NbS2 crystals that can not be dissected in such detail by averaging x-ray techniques.

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