scholarly journals Influence of the Substrate on the Electrical Properties of Thick-Film Resistors

1980 ◽  
Vol 6 (3-4) ◽  
pp. 247-251 ◽  
Author(s):  
A. Cattaneo ◽  
L. Pirozzi ◽  
B. Morten ◽  
M. Prudenziati
Keyword(s):  
Electrical Properties ◽  
Thick Film ◽  
Electron Probe ◽  
Conduction Mechanism ◽  
Gauge Factor ◽  
Substrate Type ◽  
Electron Probe Analysis ◽  
Piezoresistive Effect ◽  
X Ray ◽  
Structural Interactions

The effect of substrate type on the electrical properties of thick film resistors is determined. Five different substrates are used. The following properties are investigated: – thermal expansion, resistor profiles, resistance, TCR and resistor gauge factor. The resistors are physically inspected using X-ray diffractometry and electron probe analysis. This paper shows that conduction mechanism models for thick-film resistors generally need not take into account chemical and structural interactions with the substrate. However the effect of substrate on TCR values is significant for resistors exhibiting a large piezoresistive effect.

High-performance electrical properties of La-based perovskite ceramics for the functional phase of thick film resistors

2020 ◽  
Author(s):  
Yongcheng Lu ◽  
Yuanxun Li ◽  
Daming Chen ◽  
Rui Peng ◽  
Qinghui Yang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrical Properties ◽  
Thick Film ◽  
High Performance ◽  
Composite Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alternative Material ◽  
Perovskite Ceramics ◽  
Scanning Electron

Abstract In order to explore an economical functional phase alternative material for thick film resistors, the crystal structure, microstructure, and electrical properties of (1-x)LSCN + xLCNZ (x = 0.0–1.0) composite ceramics were studied through solid-state reaction experiments. The composite ceramics were characterized by x–ray diffraction, scanning electron microscopy, energy dispersive x–ray spectroscopy, and DC four–probe method. Results suggested that the main phases of LSCN and LCNZ were formed, along with a small part of impurity phases. The addition of LCNZ to LSCN decreased the electrical conductivity and changed the TCR from positive to negative. Zero TCR could be achieved around 0.6 < x < 0.8 and relatively low absolute TCR values could be obtained for the samples of 0.4 ≤ x ≤ 0.8. The ceramic of 0.6LSCN + 0.4LCNZ showed the optimal performances of conductivity = 1923 S/cm, TCR = 379.54 ppm/℃, and relative density = 95.05%.

A note on the occurrence of chevkinite, allanite, and zirkelite on St. Kilda, Scotland

1982 ◽  
Vol 46 (341) ◽  
pp. 445-448 ◽  
Author(s):  
R. R. Harding ◽  
R. J. Merriman ◽  
P. H. A. Nancarrow
Keyword(s):  
Rare Earth ◽  
Great Britain ◽  
Electron Probe ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
Electron Probe Analysis ◽  
Accessory Minerals ◽  
X Ray ◽  
Probe Analysis ◽  
Recorded Occurrence

AbstractThe occurrence of three accessory minerals with significant rare earth contents in Tertiary acid rocks of St. Kilda is described. Allanite, zirkelite, and chevkinite were identified by electron probe analysis (with energy-dispersive attachment) and the chevkinite confirmed by X-ray diffraction. Brief comparison is made with other Tertiary occurrences of RE minerals. This is the first recorded occurrence of chevkinite in Great Britain.

scholarly journals ELECTRON PROBE ANALYSIS OF THE CALCIUM DISTRIBUTION IN CELLS OF THE EMBRYONIC CHICK CHORIOALLANTOIC MEMBRANE I. A CRITICAL EVALUATION OF TECHNIQUES

1972 ◽  
Vol 20 (6) ◽  
pp. 401-413 ◽  
Author(s):  
JAMES R. COLEMAN ◽  
A. RAYMOND TEREPKA
Keyword(s):  
Electron Probe ◽  
Critical Evaluation ◽  
Chorioallantoic Membrane ◽  
Embryonic Chick ◽  
Total Calcium ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Chick Chorioallantoic Membrane ◽  
Minor Losses

The chorioallantoic membrane of the developing chick embryo is an epithelium that actively transports calcium. The methodology utilized to prepare this soft tissue for calcium localization with the electron probe x-ray microanalyzer is presented in detail. The preparative procedures are evaluated according to general histochemical principles and in relationship specifically to electron probe investigations. It is shown that the method employed in these studies preserves the normal fine structure of the tissue, prevents selective loss of calcium, permits only minor losses of total calcium and appears to maintain the distribution of calcium that existed in vivo. Examples are presented of artifacts that can be induced during tissue sectioning and mounting procedures. Problems of defining electron probe resolution in biologic specimens are discussed, and the critical importance of evaluating x-ray images in association with simultaneously generated sample current images is emphasized.

Electron Probe Microanalysis of Zinc-Bearing Hexagonal Ferrites

1965 ◽  
Vol 9 ◽  
pp. 304-313
Author(s):  
J. R. Shappirio
Keyword(s):  
Electron Probe ◽  
Hexagonal Ferrites ◽  
Structural Units ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Layer Structures ◽  
Cell Data ◽  
Unit Cell Data ◽  
The Ideal

AbstractThe electron probe is shown to be an effective tool for the analysis of the series of ferrimagnetic oxides referred to as the hexagonal ferrites. This series of compounds) containing barium, Fe3+, and a divalent metal cation, is formed by an ordered stacking of basic structural units in varying ratios. The ideal, complex stoichiornewy of these polytype-like mixed-layer structures can be computed from X-ray unit cell data; the various structures and their predicted stoichiometry are reviewed. Results of electron probe analysis of zinc-bearing single-crystal hexagonal ferrites are compared with theoretical values, the various correction procedures applied to the probe data are presented, and the limitations of the method in the analysis of hexagonal ferrites are discussed. The information obtained from this study has laid the groundwork for the determination of chemistry in substituted members of the hexagonal ferrite group, and will contribute significantly to the interpretation of the magnetic properties exhibited by these compounds.

Cosmochlore—a new examination

1981 ◽  
Vol 44 (335) ◽  
pp. 265-267 ◽  
Author(s):  
A. G. Couper ◽  
M. H. Hey ◽  
R. Hutchison
Keyword(s):  
Electron Probe ◽  
Optical Data ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Probe Analysis

AbstractExamination of cotype cosmochlore from the Toluca meteorite confirms Laspeyres's observations (1897) in every respect, except that what he determined as iron was largely titanium. His data are completed by an electron-probe analysis and by full optical and X-ray data. Accepting the identity of cosmochlore and ureyite, the optical data of Frondel and Klein (1965) for the latter are partly in error or misprinted.

scholarly journals Untersuchungen am System Vanadium—Gallium

1966 ◽  
Vol 21 (5) ◽  
pp. 531-540 ◽  
Author(s):  
R. G. Maier ◽  
Y. Uzel ◽  
H. Kandler
Keyword(s):  
Crystal Structure ◽  
Phase Diagram ◽  
Electron Probe ◽  
Liquidus Curve ◽  
X Ray Diffraction ◽  
Equilibrium Conditions ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Oxygen System ◽  
Annealing Experiments

The phase diagram of the vanadium-gallium system was investigated by means of thermoanalysis, microscopy, x-ray diffraction, and electron probe analysis.The liquidus curve was measured in the range from 40—80% Gallium. The existence of the known phases V3Ga (Cr3Si-typ), V6Ga5 (Ti6Sn5-typ), V6Ga7 (Cu5Zn8-typ), V2Ga5 (Mn2Hg5-typ), V4GaO and V5Ga3Ox (Mn5Si3-typ) was reestablished. The existence of V3GaOx and V5 (Ga, Si)3Ox is stated and their crystal structure investigated.It is shown that the oxygen content of he samples greatly influences the equilibrium conditions of the system. By means of annealing experiments and dilatometric measurements the phase diagram of the vanadium-gallium-oxygen system was investigated in the range of small oxygen contents.

scholarly journals Arsenic-induced bone marrow toxicity: ultrastructural and electron- probe analysis

Blood ◽  
1979 ◽  
Vol 53 (5) ◽  
pp. 820-827 ◽  
Author(s):  
JR Feussner ◽  
JD Shelburne ◽  
S Bredehoeft ◽  
HJ Cohen
Keyword(s):  
Bone Marrow ◽  
Electron Probe ◽  
Megaloblastic Anemia ◽  
Hematologic Toxicity ◽  
Bone Marrow Toxicity ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Arsenic Poisoning ◽  
Probe Analysis ◽  
Local Bone

A patient with severe arsenic poisoning that resulted in marked peripheral blood and bone marrow abnormalities, including megaloblastic erythropoiesis experienced many of the previously reported hematologic complications of arsenic poisoning: leukopenia, granulocytopenia, absolute eosinophilia, and profound anemia. In this study we report an ultrastructural and electron-probe analysis of the bone marrow. Although megaloblastic anemia associated with arsenic poisoning has been described rarely, the presence of arsenic in the local bone marrow milieu has not been demonstrated previously. The ultrastructural features of arsenic-induced bone marrow toxicity are similar to those described in other dyserythropoietic states and include marked nuclear aberrations involving shape, chromatin distribution, and nuclear envelope. Using the technique of energy-dispersive x-ray analysis (electron probe) we demonstrated arsenic in bone marrow spicules; this supports the contention that arsenic can cause megaloblastic anemia. We suggest that this technique may be a useful tool in further studies that attempt to explore the mechanism of arsenic-induced hematologic toxicity. Finally, we suggest that arsenic has a direct toxic effect on DNA synthesis that results in marked disturbances of nuclear division. We recommend that the most appropriate screening procedure to evaluate possible arsenic poisoning is tissue arsenic measurements (hair and nails) rather than 24-hr urinary measurements.

Electron Probe Analysis and Cell Physiology

1985 ◽  
Vol 43 ◽  
pp. 2-5
Author(s):  
A.P. Somlyo ◽  
Avril V. Somlyo
Keyword(s):  
Electron Probe ◽  
Epithelial Transport ◽  
Muscle Physiology ◽  
Cell Physiology ◽  
Cell Organelles ◽  
General Applicability ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Smooth Muscle Function ◽  
Recent Demonstration

Electron probe x-ray microanalysis (EPMA) of rapidly frozen tissues is a uniquely powerful method for dealing with a large class of general problems in cell physiology, as it is suitable for measuring, under direct vision, the elemental composition of cells and cell organelles. EPMA can reach a spatial resolution of at least 10nm, and its practically attainable sensitivity (for Ca) is 0.3mmol Ca/kg dry wt. Therefore, the composition of mitochondria and of other organelles, as small as the endoplasmic reticulum (ER), can be quantitated with EPMA. The most extensive applications of EPMA to cell physiology have been in muscle physiology and epithelial transport (for reviews). In this discussion, we will illustrate the applications of EPMA by summarizing studies from our laboratory on striated and smooth muscle function. We shall also illustrate the use of EPMA to study the effects of drugs on organelles. The general applicability of EPMA to cell transport will be illustrated, somewhat arbitrarily, through EPMA studies of vertebrate photoreceptors. We are convinced that as experience is gained, largely with the specimen preparatory techniques required, EPMA will also find increasing applications to cell pathology, as illustrated by the recent demonstration of calcium compartmentalization in sickle red blood cells.

Methods of Quantitative Electron Probe Analysis*

1963 ◽  
Vol 7 ◽  
pp. 395-418 ◽  
Author(s):  
David B. Wittry
Keyword(s):  
Electron Probe ◽  
Fluorescence Analysis ◽  
Universal Theory ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Calibration Curves ◽  
Probe Analysis ◽  
Quantitative Results ◽  
Relationship Of ◽  
The Relationship

AbstractMethods of quantitative electron probe analysis using empirical working curves have achieved only partial success because of variations in instrument design, analysis conditions, and homogeneity of standards. These problems have been solved for X-ray fluorescence analysis, but many of the more successful empirical methods cannot be used in electron probe analysis; instead, a more theoretical approach is indicated. In electron probe analysis quantitative results can be achieved with only pure elements as standards provided (1) the analysis conditions are carefully selected, (2) the observed intensities can be corrected to obtain the primary intensity actually produced in the specimen, and (3) the relationship of the primary intensity and concentration can be calculated. While present methods of making some of the corrections required improvement and a “universal” theory for relating the primary X-ray intensities to the concentrations still does not exist, the success achieved with this approach indicates that it should be used to the fullest extent before resorting to calibration curves. Moreover, as information is accumulated, the number of cases requiring the use of calibration curves should diminish, so that eventually it may be possible to perform quantitative analysis in any system with only pure elements as standards,

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