Quantitative Electron Probe Microanalysis of Bi-Sr-Ca-Cu-O High Tc Superconductors Using Energy- and Wavelength-Dispersive Spectrometry

1997 ◽  
Vol 3 (6) ◽  
pp. 504-511
Author(s):  
Ryna B. Marinenko ◽  
Mark Teplitsky
Keyword(s):  
Electron Probe ◽  
Matrix Correction ◽  
Linear Least Squares ◽  
High Tc Superconductors ◽  
Spectral Processing ◽  
High Tc ◽  
Eds Analysis ◽  
Wavelength Dispersive Spectrometry ◽  
Quantitative Electron Probe Microanalysis ◽  
Quantitative Results

Abstract: Multiple linear least squares (MLLSQ) and sequential simplex spectral processing procedures were used in an electron probe energy-dispersive (EDS) analysis of a 2223 Bi-Sr-Ca-Cu-O (BSCCO) high Tc superconductor specimen. This phase is normally difficult to quantify by EDS at voltages below 25 kV because of the severe overlap of the BiM lines with the M lines from a small amount of Pb that is added to the phase for stability. Quantitative results from the MLLSQ spectral processing and ZAF matrix correction procedures agreed well with wavelength-dispersive analysis (WDS) of the same specimen.

Electron-Probe Quantitative Energy-Dispersive Analysis of Trace Magnesium Concentrations in Ag-Mg Alloys

1996 ◽  
Vol 54 ◽  
pp. 510-511
Author(s):  
R. B. Marinenko
Keyword(s):  
Electron Probe ◽  
Energy Dispersive Spectrometry ◽  
Mg Alloys ◽  
Energy Dispersive ◽  
Energy Dispersive Analysis ◽  
High Tc ◽  
Alloy Wire ◽  
High Tc Superconductor ◽  
Eds Analysis ◽  
Superior Mechanical Properties

Internally oxidized Ag-Mg alloys are used as sheaths for high Tc superconductor wires because of their superior mechanical properties. The preparation and characteristics of these materials have been reported. Performance of the sheaths depends on the concentration of the magnesium which generally is less than 0.5 wt. percent. The purpose of this work was to determine whether electron probe microanalysis using energy dispersive spectrometry (EDS) could be used to quantitate three different Ag-Mg alloys. Quantitative EDS analysis can be difficult because the AgL escape peak occurs at the same energy (1.25 keV) as the Mg Kα peak. An EDS spectrum of a Ag-Mg alloy wire is compared to a pure Ag spectrum in Fig. 1.

Overcoming Peak Overlaps in Titanium- and Vanadium-Bearing Materials with Multiple Linear Least Squares Fitting

2017 ◽  
Vol 23 (3) ◽  
pp. 491-500 ◽  
Author(s):  
Michael Mengason ◽  
Nicholas Ritchie
Keyword(s):  
Electron Probe ◽  
Energy Dispersive Spectrometer ◽  
Silicon Detector ◽  
Energy Scale ◽  
Linear Least Squares ◽  
Silicon Drift Detector ◽  
X Ray ◽  
Naturally Occurring ◽  
Wavelength Dispersive Spectrometry ◽  
Bearing Materials

AbstractThe evolution of the energy dispersive spectrometer (EDS) from the lithium-drifted silicon detector [Si(Li)] to the silicon drift detector (SDD) has created new opportunities in the field of electron probe X-ray microanalysis. The SDD permits operation at significantly higher count rates than the Si(Li) and also provides a more stable energy scale. X-ray spectra captured by EDS can now be analyzed qualitatively or quantitatively under the same beam conditions as used for wavelength dispersive spectrometry (WDS). Standards-based quantitative EDS (SB-Quant-EDS) can thus provide analyses that are accurate and precise for an ever growing number of materials measurement problems. In this study, we analyze NIST research glasses with “known” nominal concentrations of titanium (Ti) and vanadium (V) to evaluate the external reproducibility of the SB-Quant-EDS technique in the presence of severe peak overlaps. We additionally analyze several naturally occurring oxide minerals by WDS and EDS simultaneously and evaluate the outputs of these two methods when quantifying the same analytical volume within the sample.

Structure, Composition and Superconductivity of High Tc Tl–Ba–Ca–Cu–O System

1989 ◽  
Vol 156 ◽  
Author(s):  
Yasuhiko Syono ◽  
Masae Kikuchi ◽  
Satoru Nakajima ◽  
Teruo Suzuki ◽  
Takeo Oku ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Probe ◽  
Magnetic Measurements ◽  
Chemical Compositions ◽  
Superconducting Properties ◽  
High Tc Superconductors ◽  
Critical Temperatures ◽  
High Tc ◽  
X Ray ◽  
Transmission Electron

ABSTRACTBulk high Tc superconductors of Tl2Ba2Can−1CunO2n+4 (n=1−4) and TlBa2Can−1CunO2n+3 (n=2−5) were synthesized, and their structures, chemical compositions and superconducting properties were studied by means of X-ray powder diffraction, electron probe microanalysis, transmission electron microscopy, and electrical and magnetic measurements. Superconducting critical temperatures are discussed in terms of average Cu valence and Cu-O bond length within the plane which vary with the number of Cu layers.

A robust method for determining the Duane-Hunt energy limit from EDS

1990 ◽  
Vol 48 (2) ◽  
pp. 210-211
Author(s):  
Robert L. Myklebust ◽  
Charles E. Fiori ◽  
Dale E. Newbury
Keyword(s):  
Electron Probe ◽  
Beam Energy ◽  
Potential Drop ◽  
Matrix Correction ◽  
Energy Limit ◽  
Energy Excitation ◽  
X Ray ◽  
Beam Voltage ◽  
Lower Beam ◽  
Quantitative Electron Probe Microanalysis

The electron beam energy is a parameter required for quantitative electron probe microanalysis. In fact, it occurs in all parts of the ZAF type matrix correction procedure as well as in all of the other matrix correction procedures. Recently, there has been much interest in analyzing materials using lower beam voltages. Since the correction procedures use the so called “overvoltage” term (beam energy/excitation energy), uncertainties in the beam voltage will generate larger errors than when high beam voltages are used. The user may well be faced with an instrument that does not have a very precise voltmeter to measure the beam voltage, or the reported voltage may not actually represent the potential drop from the filament to ground (specimen). The true beam energy may differ from the “measured” potential drop by several hundred volts.It is difficult and potentially exciting to measure the beam voltage with a calibrated voltmeter; however, we have a built-in method available in the energy-dispersive x-ray detector.

The many faces of STEM in materials science

1991 ◽  
Vol 49 ◽  
pp. 440-441
Author(s):  
John Silcox
Keyword(s):  
Materials Science ◽  
Auger Spectroscopy ◽  
Dark Field ◽  
High Tc Superconductors ◽  
High Tc ◽  
Acoustic Environment ◽  
Electromagnetic Vibration ◽  
The Many ◽  
Serial Mode

Determination of the microstructure and microchemistry of small features often provides the insight needed for the understanding of processes in real materials. In many cases, it is not adequate to use microscopy alone. Microdiffraction and microspectroscopic information such as EELS, X-ray microprobe analysis and Auger spectroscopy can all contribute vital parts of the picture. For a number of reasons, dedicated STEM offers considerable promise as a quantitative instrument. In this paper, we review progress towards effective quantitative use of STEM with illustrations drawn from studies of high Tc superconductors, compound semiconductors and metallization of H-terminated silicon.Intrinsically, STEM is a quantitative instrument. Images are acquired directly by detectors in serial mode which is particularly convenient for digital image acquisition, control and display. The VG HB501A at Cornell has been installed in a particularly stable electromagnetic, vibration and acoustic environment. Care has been paid to achieving UHV conditions (i.e., 10-10 Torr). Finally, it has been interfaced with a VAX 3200 work station by Kirkland. This permits, for example, the acquisition of bright field (or energy loss) images and dark field images simultaneously as quantitative arrays in perfect registration.

Crystal chemistry of high-Tc superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 1118-1119
Author(s):  
Maryvonne Hervieu
Keyword(s):  
Oxygen Deficiency ◽  
Large Family ◽  
Copper Oxides ◽  
High Tc Superconductors ◽  
High Tc ◽  
Single Mechanism ◽  
Square Planar ◽  
History Of ◽  
Bismuth Cuprates ◽  
New Compounds

Four years after the discovery of superconductivity at high temperature in the Ba-La-Cu-O system, more than thirty new compounds have been synthesized, which can be classified in six series of copper oxides: La2CuO4 - type oxides, bismuth cuprates, YBa2Cu3O7 family, thallium cuprates, lead cuprates and Nd2CuO4 - type oxides. Despite their quite different specific natures, close relationships allow their structures to be simply described through a single mechanism. The fifth first families can indeed be described as intergrowths of multiple oxygen deficient perovskite slabs with multiple rock salt-type slabs, according to the representation [ACuO3-x]m [AO]n.The n and m values are integer in the parent structures, n varying from 0 to 3 and m from 1 to 4; every member of this large family can thus be symbolized by [m,n]. The oxygen deficient character of the perovskite slabs involves the existence or the co-existence of several types of copper environment: octahedral, pyramidal and square planar.Both mechanisms, oxygen deficiency and intergrowth, are well known to give rise easily to nonstoichiometry phenomena. Numerous and various phenomena have actually been characterized in these cuprates, strongly depending on the thermal history of the samples.

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