X-ray microanalysis of thin specimens in the transmission electron microscope at voltages up to 1000 Kv.

1978 ◽  
Vol 36 (1) ◽  
pp. 540-541
Author(s):  
G. Cliff ◽  
M.J. Nasir ◽  
G.W. Lorimer ◽  
N. Ridley
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Weight Fraction ◽  
Present Series ◽  
Constant Independent ◽  
X Ray ◽  
Transmission Electron ◽  
Series Of Experiments ◽  
Image Position ◽  
X Ray Absorption

In a specimen which is transmission thin to 100 kV electrons - a sample in which X-ray absorption is so insignificant that it can be neglected and where fluorescence effects can generally be ignored (1,2) - a ratio of characteristic X-ray intensities, I1/I2 can be converted into a weight fraction ratio, C1/C2, using the equationwhere k12 is, at a given voltage, a constant independent of composition or thickness, k12 values can be determined experimentally from thin standards (3) or calculated (4,6). Both experimental and calculated k12 values have been obtained for K(11<Z>19),kα(Z>19) and some Lα radiation (3,6) at 100 kV. The object of the present series of experiments was to experimentally determine k12 values at voltages between 200 and 1000 kV and to compare these with calculated values.The experiments were carried out on an AEI-EM7 HVEM fitted with an energy dispersive X-ray detector.

Routine Determination of X-Ray Detector Efficiencies Using Submicron Spheres of Pure Materials

1985 ◽  
Vol 43 ◽  
pp. 416-417
Author(s):  
Thomas F. Kelly
Keyword(s):  
Electron Microscope ◽  
Energy Range ◽  
Transmission Electron Microscope ◽  
Weight Fraction ◽  
Characteristic Line ◽  
X Rays ◽  
Detector Efficiency ◽  
X Ray ◽  
Transmission Electron

The purpose of this paper is to outline an approach to routine determination of x-ray detector efficiencies over the entire applicable energy range that may be used on any transmission electron microscope.BACKGROUNDThe quantification of x-ray intensities using the ratio technique can be accomplished [see, for example, 1] using a relation of the form:Here, for element A, CA is the composition in the sample as a weight fraction, kA is the x-ray generation constant (see below) which contains only sample-dependent information, eA is the detector efficiency for characteristic x-rays which contains only detector-dependent information, and lA is the measured x-ray intensity in a characteristic line.

Sputter-Deposited Films as Standards for Tem X-Ray Analysis

1980 ◽  
Vol 38 ◽  
pp. 134-135
Author(s):  
A. F. Marshall ◽  
C. Zercher
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Specimen Thickness ◽  
Detector Efficiency ◽  
X Ray ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Image Position ◽  
Deposited Films

Quantitative energy dispersive x-ray analysis in the transmission electron microscope is generally obtained in the form of relative concentrations using the equation: where CA, CB are the concentrations and IA, IB are the peak intensities of elements A and B, and kAB is a constant which is independent of specimen composition and specimen thickness, assuming the thin film criterion is satisfied. kAB may be determined experimentally from standards (Cliff-Lorimer technique1), or may be calculated from considerations of x-ray generation and detector efficiency for the elements being analyzed2. Due to differences in detector parameters, kAB may vary from instrument to instrument.

Correlative electron and X-ray microscopy: probing chemistry and bonding with high spatial resolution

Nanoscale ◽  
2015 ◽  
Vol 7 (5) ◽  
pp. 1534-1548 ◽  
Author(s):  
Angela E. Goode ◽  
Alexandra E. Porter ◽  
Mary P. Ryan ◽  
David W. McComb
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Transmission Electron Microscope ◽  
High Spatial Resolution ◽  
Scanning Transmission Electron Microscope ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Energy Loss ◽  
X Ray Absorption

Benefits and challenges of correlative spectroscopy: electron energy-loss spectroscopy in the scanning transmission electron microscope (STEM-EELS) and X-ray absorption spectroscopy in the scanning transmission X-ray microscope (STXM-XAS).

Quantitative X-ray microanalysis of thin specimens in the transmission electron microscope; a review

1987 ◽  
Vol 51 (359) ◽  
pp. 49-60 ◽  
Author(s):  
G. W. Lorimer
Keyword(s):  
Weight Fraction ◽  
Bulk Sample ◽  
Thin Specimen ◽  
X Ray ◽  
Qualitative And Quantitative ◽  
First Approximation ◽  
Transmission Electron ◽  
Quantitative Analyses ◽  
Image Position ◽  
X Ray Absorption

AbstractIn a thin specimen X-ray absorption and fluorescence can, to a first approximation, be ignored and the observed X-ray intensity ratios, IA/IB, can be converted into weight fraction ratios, , can be converted into weight fraction ratios, CA/CB, by multiplying by a constant , by multiplying by a constant kAB;kAB values can be calculated or determined experimentally. The major correction which may have to be made to the calculated weight fraction ratio is for X-ray absorption within the specimen. The activated volume for analysis in a thin specimen is approximately 100 000 × less than in a bulk sample. Beam spreading within the specimen can be estimated using a simple formula based on a single elastic scattering event at the centre of the specimen. Examples are given of the application of the technique to obtain both qualitative and quantitative analyses from thin mineral specimens. The minimum detectable mass and the minimum mass fraction which can be measured using the technique are estimated.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

Thickness and composition determinations from T.E.M. specimens using both x-ray and backscattered electron data

1984 ◽  
Vol 42 ◽  
pp. 576-577
Author(s):  
M.D. Ball ◽  
H. Lagace ◽  
M.C. Thornton
Keyword(s):  
Electron Microscope ◽  
Atomic Number ◽  
Transmission Electron Microscope ◽  
Convenient Method ◽  
Flow Chart ◽  
X Ray ◽  
Intensity Measurements ◽  
Transmission Electron ◽  
Electron Intensity ◽  
Backscattered Electron

The backscattered electron coefficient η for transmission electron microscope specimens depends on both the atomic number Z and the thickness t. Hence for specimens of known atomic number, the thickness can be determined from backscattered electron coefficient measurements. This work describes a simple and convenient method of estimating the thickness and the corrected composition of areas of uncertain atomic number by combining x-ray microanalysis and backscattered electron intensity measurements.The method is best described in terms of the flow chart shown In Figure 1. Having selected a feature of interest, x-ray microanalysis data is recorded and used to estimate the composition. At this stage thickness corrections for absorption and fluorescence are not performed.

Luminescent Properties of Gd2MoO6:Eu3+ Nanophosphor for WLEDs

2021 ◽  
Author(s):  
Yan Chen ◽  
Yuemei Lan ◽  
Dong Wang ◽  
Guoxing Zhang ◽  
Wenlong Peng ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Fluorescence Spectra ◽  
Solvothermal Method ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

A series of Gd2-xMoO6:xEu3+(x=0.18-0.38) nanophosphors were synthesized by the solvothermal method. The properties of this nanophosphor were characterized by x-ray diffraction (XRD), transmission electron microscope (TEM), fluorescence spectra and diffuse...

Formation of Graphite Encapsulated Nickel Nanoparticles by Ball Milling and Annealing of Expanded Graphite with Nickel

2011 ◽  
Vol 80-81 ◽  
pp. 217-220 ◽  
Author(s):  
Xue Qing Yue ◽  
Hai Jun Fu ◽  
Da Jun Li
Keyword(s):  
Electron Microscope ◽  
Ball Milling ◽  
Transmission Electron Microscope ◽  
Nickel Nanoparticles ◽  
Size Range ◽  
Expanded Graphite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Powders ◽  
Transmission Electron

Graphite encapsulated nickel nanoparticles were prepared by ball milling andsubsequently annealing a mixture of expanded graphite with nickel powders. The products were characterized by transmission electron microscope and X-ray diffraction. The formation mechanism of the products was discussed. Results show that the products have a size range of 20-150 nm. The graphite and nickel in the products all exhibit a high crystallinity.

Template Induced Synthesis of Nano-Hydroxyapatite by Co-Precipitation Method

2011 ◽  
Vol 311-313 ◽  
pp. 1713-1716 ◽  
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Chang An Wang ◽  
Li Guo Ma ◽  
Feng Liu
Keyword(s):  
Electron Microscope ◽  
Chondroitin Sulfate ◽  
Aspartic Acid ◽  
Transmission Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Co Precipitation

Nano-hydroxyapatite with different morphology was synthesized by the co-precipitation method coupled with biomineralization using Ca(NO3)2•4H2O and (NH4)2HPO4 as reagents, adding chondroitin sulfate, agarose and aspartic acid as template. The structure and morphology of the prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM).

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