Interfacial Effects in Polycaproamide-Aramide Polymer Systems

1993 ◽  
Vol 318 ◽  
Author(s):  
Vladimir P. Dmitrenko
Keyword(s):  
Phase Equilibrium ◽  
Thermal Treatment ◽  
Phase Diagrams ◽  
Electron Probe ◽  
Effect Of Temperature ◽  
Transitional Layer ◽  
Polymer Systems ◽  
Interfacial Effects ◽  
X Ray ◽  
Kinetics Of

ABSTRACTThe peculiarity of interdiffusion and phase equilibrium has been studied for poly-m-phenyleneisophthalamide and poly-p-amidobenzimidazole systems during formation of a transitional layer in conditions of organoplastics. The investigation of this process has been based on the method of electron-probe X-ray spectral microanalysis. The effect of temperature, pressure and time of thermal treatment on dimensions of diffusional zones and kinetics of their formation was shown. The parameters of solubility and mutual diffusion of components were determined and phase diagrams were obtained.

Diffusion and Electromigration of Cu in Single Crystal Al Interconnects

1998 ◽  
Vol 516 ◽  
Author(s):  
V. T. Srikar ◽  
C. V. Thompson
Keyword(s):  
Grain Boundary ◽  
Single Crystal ◽  
Concentration Profile ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Effect Of Temperature ◽  
Cu Alloys ◽  
Grain Structures ◽  
Kinetics Of ◽  
Grain Boundary Transport

AbstractThe electromigration-induced transport properties of Cu in Al-Cu alloys, and their effect on electromigration lifetimes in interconnects with bamboo grain structures are not well understood. To isolate and study the mechanisms and kinetics of Cu diffusion and electromigration in interconnects for which grain boundary transport is not dominant, we have developed a test structure consisting of parallel Al single crystal lines, with every alternate line terminating in contact pads. Cu is locally added to the same regions in all the lines, and the effect of temperature and electric field can be simultaneously characterized by analyzing the Cu concentration profile measured using electron-probe microanalysis. Comparison of the calculated values of diffusivities with the diffusivity of Cu through the Al lattice, and through dislocation cores in Al, suggests that the path of diffusion of Cu in Al single crystals is along the Al/AlOx interface.

scholarly journals Leaching Kinetics of Arsenic Sulfide-Containing Materials by Copper Sulfate Solution

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Kirill A. Karimov ◽  
Denis A. Rogozhnikov ◽  
Evgeniy A. Kuzas ◽  
Andrei A. Shoppert
Keyword(s):  
Copper Sulfate ◽  
Raw Materials ◽  
Sulfate Solution ◽  
Effect Of Temperature ◽  
Arsenic Sulfide ◽  
Copper Sulfate Solution ◽  
X Ray ◽  
Shrinking Core ◽  
Multicomponent Solutions ◽  
Kinetics Of

The overall decrease in the quality of mineral raw materials, combined with the use of arsenic-containing ores, results in large amounts of various intermediate products containing this highly toxic element. The use of hydrometallurgical technologies for these materials is complicated by the formation of multicomponent solutions and the difficulty of separating copper from arsenic. Previously, for the selective separation of As from copper–arsenic intermediates a leaching method in the presence of Cu(II) ions was proposed. This paper describes the investigation of the kinetics of arsenic sulfide-containing materials leaching by copper sulfate solution. The cakes after leaching of arsenic trisulfide with a solution of copper sulfate were described using methods such as X-ray diffraction spectrometry (XRD), X-ray fluorescence spectrometry (XRF), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy analysis (EDS). The effect of temperature (70–90 °C), the initial concentration of CuSO4 (0.23–0.28 M) and the time on the As recovery into the solution was studied. The process temperature has the greatest effect on the kinetics, while an increase in copper concentration from 0.23 to 0.28 M effects an increase in As transfer into solution from 93.2% to 97.8% for 120 min of leaching. However, the shrinking core model that best fits the kinetic data suggests that the process occurs by the intra-diffusion mode with the average activation energy of 44.9 kJ/mol. Using the time-to-a-given-fraction kinetics analysis, it was determined that the leaching mechanism does not change during the reaction. The semi-empirical expression describing the reaction rate under the studied conditions can be written as follows: 1/3ln(1 − X) + [(1 − X) − 1/3 − 1] = 4560000Cu3.61e−44900/RT t.

UMo/Al nuclear fuel plate behavior under thermal treatment (425-550°C)

2013 ◽  
Vol 28 (S2) ◽  
pp. S371-S393 ◽  
Author(s):  
H. Palancher ◽  
A. Bonnin ◽  
C.V. Colin ◽  
V. Nassif ◽  
V. Honkimäki ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Thermal Behavior ◽  
Nuclear Fuel ◽  
High Energy ◽  
X Ray Diffraction ◽  
Research Reactors ◽  
Interaction Layer ◽  
X Ray ◽  
Basic Work ◽  
Kinetics Of

Nuclear fuel plates based on a γU-Mo/Al mixture are proposed for research reactors. In this work their thermal behavior in the [425; 550°C] temperature range has been studied mainly by neutron and high energy X-ray diffraction. Even if complementary studies will be necessary, the kinetics of first the growth of the interaction layer between γU-Mo and Al and second of the γU-Mo destabilization have been accurately measured. This basic work should be helpful for defining manufacturing conditions for fuel plates with optimized composition.

Stable and Metastable Phases in the Systems AgI-Ag2XO4 (X=Cr, Mo, W)

1976 ◽  
Vol 31 (8) ◽  
pp. 974-977 ◽  
Author(s):  
Aldo Magistris ◽  
Gaetano Chiodelli ◽  
Giuseppina Viganò Campari
Keyword(s):  
Ionic Conductivity ◽  
Thermal Treatment ◽  
Phase Diagrams ◽  
Room Temperature ◽  
Composition Range ◽  
Metastable Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Third ◽  
Stable And Metastable Phases

Abstract DTA and powder x-ray diffraction measurements allowed to draw the phase diagrams of the systems AgI-Ag2XO4 (X = Cr, Mo, W). A more detailed investigation was devoted to the composition range around XAgI = 0.8, where in preliminary tests it was observed that the room temperature ionic conductivity strongly depends on the thermal treatment of the sample. By quenching mixtures at XAgI = 0.8, glass-like phases with high conductivity were obtained; in the systems AgI-Ag2CrO4 and AgI-Ag2MO4 the subsequent crystallization gave rise to non con-ducting phases, whereas the occurrence of the highly conducting compound 4AgI·Ag2WO4 was recognized in the third system investigated.

Effect of temperature on the phase equilibrium of aqueous two-phase polymer systems

AIChE Journal ◽  
1993 ◽  
Vol 39 (12) ◽  
pp. 1976-1984 ◽  
Author(s):  
H. Hartounian ◽  
E. Floeter ◽  
E. W. Kaler ◽  
S. I. Sandler
Keyword(s):  
Phase Equilibrium ◽  
Effect Of Temperature ◽  
Two Phase ◽  
Polymer Systems

Slow Aggregation of Titania Nanocrystals in Acidic Hydrosols

2011 ◽  
Vol 1352 ◽  
Author(s):  
Olga Pavlova-Verevkina ◽  
Ludmila Ozerina ◽  
Natalia Golubko ◽  
Abdelkrim Chemseddine
Keyword(s):  
Thermal Treatment ◽  
Small Angle ◽  
Room Temperature ◽  
Initial Rate ◽  
Low Ph ◽  
X Ray ◽  
X Ray Scattering ◽  
Slow Aggregation ◽  
Kinetics Of ◽  
Hcl Solution

ABSTRACTThe kinetics of slow aggregation of monodisperse TiO2 nanocrystals in the acidic hydrosols at room temperature was studied for months by turbidimetry. The dependence of the initial rate of aggregation on the pH was calculated. The comparison of results obtained by turbidimetry and small angle X-ray scattering permits to suppose that very loose aggregates form at the low pH in HCl solution. The dependencies obtained in this work for room temperature can be taken into consideration at the tuning of TiO2 nanoparticles morphology through thermal treatment of hydrosols.

Improvements in the electron probe forming capabilities and x-ray hole counts in the Philips TEM

1983 ◽  
Vol 41 ◽  
pp. 376-377
Author(s):  
Richard L. McConville
Keyword(s):  
Field Strength ◽  
Electron Probe ◽  
Spherical Aberration ◽  
Focal Length ◽  
Objective Lens ◽  
Parallel Beam ◽  
Tilt Axis ◽  
X Ray ◽  
Small Probe ◽  
Specimen Height

A second generation twin lens has been developed. This symmetrical lens with a wider bore, yet superior values of chromatic and spherical aberration for a given focal length, retains both eucentric ± 60° tilt movement and 20°x ray detector take-off angle at 90° to the tilt axis. Adjust able tilt axis height, as well as specimen height, now ensures almost invariant objective lens strengths for both TEM (parallel beam conditions) and STEM or nano probe (focused small probe) modes.These modes are selected through use of an auxiliary lens situ ated above the objective. When this lens is on the specimen is illuminated with a parallel beam of electrons, and when it is off the specimen is illuminated with a focused probe of dimensions governed by the excitation of the condenser 1 lens. Thus TEM/STEM operation is controlled by a lens which is independent of the objective lens field strength.

Spatial resolution of X-ray microanalysis in thin foils

1978 ◽  
Vol 36 (1) ◽  
pp. 544-545
Author(s):  
R. Hutchings ◽  
I.P. Jones ◽  
M.H. Loretto ◽  
R.E. Smallman
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Beam Divergence ◽  
Inelastic Interaction ◽  
Specimen Thickness ◽  
High Current ◽  
Beam Spreading ◽  
X Ray ◽  
Thin Foils ◽  
Complex Calculation

There is increasing interest in X-ray microanalysis of thin specimens and the present paper attempts to define some of the factors which govern the spatial resolution of this type of microanalysis. One of these factors is the spreading of the electron probe as it is transmitted through the specimen. There will always be some beam-spreading with small electron probes, because of the inevitable beam divergence associated with small, high current probes; a lower limit to the spatial resolution is thus 2αst where 2αs is the beam divergence and t the specimen thickness.In addition there will of course be beam spreading caused by elastic and inelastic interaction between the electron beam and the specimen. The angle through which electrons are scattered by the various scattering processes can vary from zero to 180° and it is clearly a very complex calculation to determine the effective size of the beam as it propagates through the specimen.

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.

High spatial resolution x-ray microanalysis of interfaces

1995 ◽  
Vol 53 ◽  
pp. 284-285
Author(s):  
J. R. Michael
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Solid Angle ◽  
Collection Efficiency ◽  
Spatial Scales ◽  
Energy Dispersive Spectrometer ◽  
X Rays ◽  
X Ray ◽  
Probe Size ◽  
Brightness Field

X-ray microanalysis in the analytical electron microscope (AEM) refers to a technique by which chemical composition can be determined on spatial scales of less than 10 nm. There are many factors that influence the quality of x-ray microanalysis. The minimum probe size with sufficient current for microanalysis that can be generated determines the ultimate spatial resolution of each individual microanalysis. However, it is also necessary to collect efficiently the x-rays generated. Modern high brightness field emission gun equipped AEMs can now generate probes that are less than 1 nm in diameter with high probe currents. Improving the x-ray collection solid angle of the solid state energy dispersive spectrometer (EDS) results in more efficient collection of x-ray generated by the interaction of the electron probe with the specimen, thus reducing the minimum detectability limit. The combination of decreased interaction volume due to smaller electron probe size and the increased collection efficiency due to larger solid angle of x-ray collection should enhance our ability to study interfacial segregation.

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