SELF-DIFFUSION IN POLYCRYSTALLINE NICKEL

1959 ◽  
Vol 37 (10) ◽  
pp. 1623-1628 ◽  
Author(s):  
J. R. MacEwan ◽  
J. U. MacEwan ◽  
L. Yaffe
Keyword(s):  
Grain Boundary ◽  
Boundary Diffusion ◽  
Volume Diffusion ◽  
Grain Boundary Diffusion ◽  
The Self ◽  
Polycrystalline Nickel ◽  
Self Diffusion ◽  
Diffusion Studies

The self-diffusion of nickel has been studied in polycrystalline samples by a sectioning technique. There is evidence of grain boundary diffusion below temperatures of 1150 °C. The results obtained between 1150° and 1400 °C are representative of volume diffusion and are represented by the expression[Formula: see text]A comparison is made with the results of other self-diffusion studies using Zener's hypothesis.

Zinc Self-Diffusion in ZnO

2005 ◽  
Vol 237-240 ◽  
pp. 163-168 ◽  
Author(s):  
M.A.N. Nogueira ◽  
Antônio Claret Soares Sabioni ◽  
Wilmar Barbosa Ferraz
Keyword(s):  
Diffusion Coefficient ◽  
Grain Boundary ◽  
Diffusion Coefficients ◽  
Boundary Diffusion ◽  
Volume Diffusion ◽  
Grain Boundary Diffusion ◽  
Polished Surface ◽  
Self Diffusion ◽  
Zinc Diffusion ◽  
Diffusion Profiles

This work deals with the study of zinc self-diffusion in ZnO polycrystal of high density and of high purity. The diffusion experiments were performed using the 65Zn radioactive isotope as zinc tracer. A thin film of the tracer was deposited on the polished surface of the samples, and then the diffusion annealings were performed from 1006 to 1377oC, in oxygen atmosphere. After the diffusion treatment, the 65Zn diffusion profiles were established by means of the Residual Activity Method. From the zinc diffusion profiles were deduced the volume diffusion coefficient and the product dDgb for the grain-boundary diffusion, where d is the grain-boundary width and Dgb is the grain-boundary diffusion coefficient. The results obtained for the volume diffusion coefficient show good agreement with the most recent results obtained in ZnO single crystals using stable tracer and depth profiling by secondary ion mass spectrometry, while for the grain-boundary diffusion there is no data published by other authors for comparison with our results. The zinc grain-boundary diffusion coefficients are ca. 4 orders of magnitude greater than the volume diffusion coefficients, in the same experimental conditions, which means that grain-boundary is a fast path for zinc diffusion in polycrystalline ZnO.

Measurement of the Impurity Diffusivity of Cu in Fe by Laser Induced Breakdown Spectrometry

2005 ◽  
Vol 237-240 ◽  
pp. 266-270 ◽  
Author(s):  
Chan Gyu Lee ◽  
Jung Han Lee ◽  
Byeong Seon Lee ◽  
Yong Ill Lee ◽  
Toshitada Shimozaki ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Diffusion Coefficients ◽  
Boundary Diffusion ◽  
Volume Diffusion ◽  
Diffusion Mechanism ◽  
Grain Boundary Diffusion ◽  
Impurity Diffusion ◽  
Boundary Diffusion Coefficient ◽  
Laser Induced Breakdown ◽  
Good Agreement

The impurity diffusion coefficients of Cu in Fe have been determined in the temperature range of 1073 - 1163 K by means of Laser Induced Breakdown Spectrometry (LIBS). The volume diffusion coefficients for Cu impurity diffusion in a-iron found in this work are in good agreement with the previously published result. The grain boundary diffusion coefficient gb D s d was also calculated using the volume diffusivity and processing the tails of the measured profiles. The values of the activation energy for volume and grain boundary diffusion were approximately 280 and 161 kJmol-1, respectively. This indicates the possibility of a monovacancy diffusion mechanism in case of volume diffusion. The results for the diffusion coefficients are Dv= 2.2 ×10-2exp(-280 kJmol-1/RT) m2s-1 and gb D s d = 2.6 ×10-11exp(-161 kJmol-1/RT) m3s-1.

scholarly journals ANALYSIS USING ELECTROLYTIC LAYER STRIPPING TO DETERMINE THE PARAMETERS OF GRAIN-BOUNDARY DIFFUSION OF COBALT IN POLYCRYSTALLINE NICKEL

2020 ◽  
Vol 12 (4) ◽  
pp. 62-69
Author(s):  
A.Yu. Istomina ◽  
◽  
E.V. Osinnikov ◽  
Keyword(s):  
Grain Boundary ◽  
Boundary Diffusion ◽  
Residual Activity ◽  
Grain Boundary Diffusion ◽  
Reference Source ◽  
Diffusion Annealing ◽  
Layer By Layer ◽  
Polycrystalline Nickel ◽  
Radiometric Analysis ◽  
Boundary Triple

A technique for layer-by-layer radiometric analysis using electrolytic layer stripping to determine the parameters of grain-boundary diffusion of cobalt in polycrystalline nickel has been developed. The aim of the work is to develop a complete technological cycle of layer-by-layer radiometric analysis, to select the optimal electrolyte composition for nickel and the conditions for conducting an experiment to remove metal layers with their thickness of 20–200 nm. The studies have been carried out on nickel of nominal purity of 99,98 %. The stabilizing heat treatment of the samples is carried out at a pressure of 10–5 Pa for 2 hours at a temperature of 1273 K. Diffusion annealing is carried out at a pressure of 10–9 Pa in the temperature range of 623–1173 K for 5–30 hours. Concentration profiles have been measured by parallel stripping of layers, which are obtained by electrolytic polishing in a solution based on nickel sulfamate, followed by weighing the sample on a high-precision analytical balance. The difference in weight before and after removal of the layers is used to further calculate the thickness of the removed layers and, as a consequence, the penetration depth of the diffusing. The residual activity of the sample is measured using a digital gamma spectrometer with a NaI (Tl) detector. Before carrying out the experiments, a reference source with a previously known activity has been made to take into account the correction factor due to the radioactive decay of 57Co. The specific layer activity is calculated from the integral remainder of the 122,14 keV line using the Gruzin method. Based on the proposed technique, it is possible to determine the parameters of grain boundary diffusion, such as the diffusion coefficient of grain boundary, triple product and segregation coefficient.

scholarly journals Grain boundary diffusion of chromium in polycrystalline nickel studied by SIMS

Materialia ◽  
2019 ◽  
Vol 6 ◽  
pp. 100283 ◽  
Author(s):  
Thomas Gheno ◽  
François Jomard ◽  
Clara Desgranges ◽  
Laure Martinelli
Keyword(s):  
Grain Boundary ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Polycrystalline Nickel

Oxygen Self-Diffusion In Mgo Grain Boundaries

1994 ◽  
Vol 357 ◽  
Author(s):  
Michael Liberatore ◽  
Bernhardt J. Wuensch
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Experimental Error ◽  
Boundary Diffusion ◽  
High Energy ◽  
Activation Energies ◽  
Grain Boundary Diffusion ◽  
Low Energy ◽  
Enhanced Diffusion ◽  
Self Diffusion

AbstractOxygen grain boundary diffusion has been studied in low energy (∑5, ∑13) and high energy (asymmetric 16° tilt) MgO grain boundaries. Enhanced diffusion of oxygen was observed in all boundaries, but more so in the general, high energy boundary, by 1 - 2 orders of magnitude. This supports the theory that the better the atomic registry between the adjoining grains the lower the diffusivities in the grain boundary. Also the activation energies for bulk and grain boundary diffusion (in the ∑13 boundaries) were found to be equal to within experimental error. (≈ 3.9eV)

Self-diffusion in cr2o3III. Chromium and oxygen grain-boundary diffusion in polycrystals

1992 ◽  
Vol 66 (3) ◽  
pp. 361-374 ◽  
Author(s):  
A. C. S. Sabioni ◽  
A. M. Huntz ◽  
F. Millot ◽  
C. Monty
Keyword(s):  
Grain Boundary ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Self Diffusion

GRAIN BOUNDARY DIFFUSION OF BULK INTERSTITIALS IN ALPHA-ZIRCONIUM

1990 ◽  
Vol 51 (C1) ◽  
pp. C1-691-C1-696 ◽  
Author(s):  
K. VIEREGGE ◽  
R. WILLECKE ◽  
Chr. HERZIG
Keyword(s):  
Grain Boundary ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion
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