Ru Self-Diffusion and Ru Diffusion in Al

2005 ◽  
Vol 237-240 ◽  
pp. 402-407 ◽  
Author(s):  
Fanny Dyment ◽  
Silvia Balart ◽  
Constanza Lugo ◽  
Rodolfo A. Pérez ◽  
Nicolás Di Lalla ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Pure Aluminum ◽  
The Self ◽  
Small Range ◽  
Temperature Range ◽  
Self Diffusion ◽  
Diffusion Parameters ◽  
Order Of Magnitude

The self-diffusion of Ru in the temperature range of (1267-1373) K and the Ru diffusion in pure aluminum in the temperature range of (632-873) K is reported. Difficulties were encountered when working with Ru as matrix (its brittleness at room temperature impeded a good sectioning) and they are the reason why only the order of magnitude of the self-diffusion in the small range of temperature studied is given. For Ru diffusion in aluminum, two experimental techniques were used: the conventional serial sectioning with use of a radiotracer, 103Ru, for the highest temperatures and Heavy Ions Rutherford Backscattering Spectrometry (HIRBS) for the lowest ones. The diffusion parameters are: Q = 199.4 kJ/mol and D0 = 4.1x10-2 m2/s. A comparison is made with Ru diffusion behavior in copper and silver.

Temperature Dependence of the Self-Assembled Styrene Based Random Ionomers in Aqueous Solution

2003 ◽  
Vol 775 ◽  
Author(s):  
Sung-Hwa Oh ◽  
Ju-Myung Song ◽  
Joon-Seop Kim ◽  
Hyang-Rim Oh ◽  
Jeong-A Yu
Keyword(s):  
Partition Coefficients ◽  
Room Temperature ◽  
Aqueous Media ◽  
The Self ◽  
Spectroscopic Methods ◽  
Ion Content ◽  
Repeat Units ◽  
Notable Effect ◽  
Order Of Magnitude ◽  
Experimental Errors

AbstractSolution behaviors of poly(styrene-co-sodium methacrylate) were studied by fluorescence spectroscopic methods using pyrene as a probe. The mol% of methacrylate was in the range 3.6–9.4. Water and N,N-dimethylforamide(DMF) mixture was used as a solvent (DMF/water = 0.2 mol %). The critical micelle (or aggregation) concentrations of ionomers and the partition coefficients of pyrene were obtained the temperature range 10–80°C. At room temperature, the values of CMCs (or CACs) were in the range 4.7 ×10-6 5.3 ×10-6 g/mL and we could not find any notable effect of the content of ionic repeat units within the experimental errors. Unlike CMCs, as the ion content increased, partitioning of pyrene between the hydrophobic aggregates and an aqueous media decreased from 1.5 ×105 to 9.4 ×104. As the temperature increased from 10 to 80 °C, the values of CMCs increased less than one order of magnitude. While, the partition coefficients of pyrene decreased one order of magnitude and the effect of the ion content became negligible.

Ti diffusion in feldspar

2020 ◽  
Vol 105 (7) ◽  
pp. 1040-1051
Author(s):  
D. J. Cherniak ◽  
E. B. Watson
Keyword(s):  
Trace Elements ◽  
Silica Glass ◽  
Rutherford Backscattering Spectrometry ◽  
Chemical Diffusion ◽  
Calcic Plagioclase ◽  
Crustal Rocks ◽  
Temperature Range ◽  
Chemical Signatures ◽  
Order Of Magnitude ◽  
Diffusion Profiles

Abstract Chemical diffusion of Ti has been measured in natural K-feldspar and plagioclase. The sources of diffusant used were TiO2 powders or pre-annealed mixtures of TiO2 and Al2O3. Experiments were run in crimped Pt capsules in air or in sealed silica glass capsules with solid buffers (to buffer at NNO). Rutherford backscattering spectrometry (RBS) was used to measure Ti diffusion profiles. From these measurements, the following Arrhenius relations are obtained for diffusion normal to (001):For oligoclase, over the temperature range 750–1050 °C:DOlig=6.67×10-12exp(-207±31kJ/mol/RT)m2s-1For labradorite, over the temperature range 900–1150 °C:DLab=of4.37×10-14exp(-181±57kJ/mol/RT)m2s-1For K-feldspar, over the temperature range 800–1000 °C:DKsp=3.01×10-6exp(-342±47kJ/mol/RT)m2s-1. Diffusivities for experiments buffered at NNO are similar to those run in air, and the presence of hydrous species appears to have little effect on Ti diffusion. Ti diffusion also shows little evidence of anisotropy. In plagioclase, there appears to be a dependence of Ti diffusion on An content of the feldspar, with Ti diffusing more slowly in more calcic plagioclase. This trend is similar to that observed for other cations in plagioclase, including Sr, Pb, Ba, REE, Si, and Mg. In the case of Ti, an increase of 30% in An content would result in an approximate decrease in diffusivity of an order of magnitude. These data indicate that feldspar should be moderately retentive of Ti chemical signatures, depending on feldspar composition. Ti will be more resistant to diffusional alteration than Sr. For example, Ti zoning on a 50 μm scale in oligoclase would be preserved at 600 °C for durations of ~1 million years, with Sr zoning preserved only for ~70 000 yr at this temperature. These new data for a trace impurity that is relatively slow-diffusing and ubiquitous in feldspars (Hoff and Watson 2018) have the potential to extend the scope and applicability of t-T models for crustal rocks based on measurements of trace elements in feldspars.

Self-Diffusion of Tl+ in Molten Thalium Nitrate

1977 ◽  
Vol 32 (12) ◽  
pp. 1433-1434
Author(s):  
S. Zuca ◽  
M. Constantinescu
Keyword(s):  
Diffusion Coefficient ◽  
Melting Point ◽  
The Self ◽  
Ionic Interactions ◽  
Temperature Range ◽  
Self Diffusion ◽  
Capillary Method ◽  
Self Diffusion Coefficient

Abstract The self-diffusion coefficient of Tl+ in molten TlNO3 in a temperature range of about 100° above the melting point was measured by the "diffusion-into-the capillary" method. The obtained results are discussed in terms of ionic interactions occuring in TlNO3 melt.

scholarly journals The principal magnetic susceptibilities of some paramagnetic crystals at low temperatures

1933 ◽  
Vol 140 (842) ◽  
pp. 695-713 ◽  
Keyword(s):  
Ammonium Sulphate ◽  
Low Temperatures ◽  
Room Temperature ◽  
Manganese Carbonate ◽  
Small Range ◽  
Restricted Range ◽  
Nickel Sulphate ◽  
Temperature Range ◽  
Naturally Occurring ◽  
Ferrous Carbonate

Our knowledge of the temperature variation of the principal susceptibilities of paramagnetic crystals is as yet fragmentary. The principal susceptibilities of a number of paramagnetic crystals have been determined by Finke and by Rabi at room temperature but the first measurements on orientated crystals over any range of temperature were those of Foëx. He has published the principal susceptibilities of siderose (a mineral which is mainly ferrous carbonate but which contains appreciable quantities of the carbonates of manganese and other metals) over the range 87° to 400°K. and some measurements but not actual principal susceptibilities for manganese sulphate, MnSO 4 .4H 2 O. The writer measured the principal susceptibilities of cobalt ammonium sulphate and nickel sulphate, NiSO 4 . 7H 2 O over the temperature range 14°-290°K. and the writer and de Haas have published measurements on manganese ammonium sulphate crystals over the restricted range 14°-20° K. In addition Dupouy has repeated Foëx’s observations on siderose and has measured the principal susceptibilities of dialogite (a naturally occurring manganese carbonate) and oligist (Fe 2 O 3 ), all over a small range of temperature above 0° C. Quite recently Bartlett has employed Rabi’s method to determine the principal susceptibilities of the following compounds, CoSO 4 . 7H 2 O, CoSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O, CoSO 4 . K 2 SO 4 . 6H 2 O, CuSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O CuSO 4 . K 2 SO 4 . 6H 2 O, NiSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O over the temperature range —45° to +55°C. In the writer’s opinion, however, Bartlett’s procedure is liable to several objections.

Diffusion of Nb in Nb-H Alloys

2005 ◽  
Vol 237-240 ◽  
pp. 346-351
Author(s):  
Yoshihiro Yamazaki ◽  
Takahiro Iida ◽  
Yoshiaki Iijima ◽  
Yuh Fukai
Keyword(s):  
Diffusion Coefficient ◽  
Activation Energies ◽  
The Self ◽  
Exponential Factor ◽  
Temperature Range ◽  
Self Diffusion ◽  
Diffusion Enhancement ◽  
The Difference ◽  
Self Diffusion Coefficient ◽  
Hydrogen Dissolution

Self-diffusion coefficient of 95Nb in NbHx alloys (x=0.05,0.25 and 0.3) has been determined in the temperature range from 823 to 1323 K by using a serial sputter-microsectioning technique. The self-diffusion coefficient of Nb in the NbHx alloys are larger than that in Nb, suggesting that vacancies are formed by hydrogen dissolution, that is, the formation of hydrogen-induced vacancies. The value of the pre-exponential factor for the Nb diffusion in the NbH0.05 alloy is five times larger than that in Nb, while the difference in the activation energies between the NbH0.05 alloy and pure Nb is small. The self-diffusion enhancement in the NbH0.05 alloy is mainly caused by lowering in vibrational frequencies of atoms in the immediate neighborhood of hydrogen-induced vacancies.

Al and Si diffusion in rutile

2019 ◽  
Vol 104 (11) ◽  
pp. 1638-1649 ◽  
Author(s):  
Daniele J. Cherniak ◽  
E. Bruce Watson
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Nuclear Reaction Analysis ◽  
Tio2 Powder ◽  
Powder Mixtures ◽  
Natural Systems ◽  
Temperature Range ◽  
Diffusion Parameters ◽  
Natural Rutile ◽  
Compositional Information ◽  
Ti In Quartz

Abstract Diffusion of Al and Si has been measured in synthetic and natural rutile under anhydrous conditions. Experiments used Al2O3 or Al2O3-TiO2 powder mixtures for Al diffusant sources, and SiO2-TiO2 powder mixtures or quartz-rutile diffusion couples for Si. Experiments were run in air in crimped Pt capsules, or in sealed silica glass ampoules with solid buffers (to buffer at NNO or IW). Al profiles were measured with Nuclear Reaction Analysis (NRA) using the reaction 27Al(p,γ)28Si. Rutherford Backscattering spectrometry (RBS) was used to measure Si diffusion profiles, with RBS also used in measurements of Al to complement NRA profiles. We determine the following Arrhenius relations from these measurements: For Al diffusion parallel to c, for experiments buffered at NNO, over the temperature range 1100–1400 °C: D Al = 1.21 × 10 − 2 exp ⁡ ( − 531 ± 27 kJ/ mol − 1 / RT ) m 2 s − 1 . For Si diffusion parallel to c, for both unbuffered and NNO-buffered experiments, over the temperature range 1100–1450 °C: D Si = 8.53 × 10 − 13 exp ⁡ ( − 254 ± 31   kJ/ mol − 1 / RT ) m 2 s − 1 . Diffusion normal to (100) is similar to diffusion normal to (001) for both Al and Si, indicating little diffusional anisotropy for these elements. Diffusivities measured for synthetic and natural rutile are in good agreement, indicating that these diffusion parameters can be applied in evaluating diffusivities in rutile in natural systems Diffusivities of Al and Si for experiments buffered at IW are faster (by a half to three-quarters of a log unit) than those buffered at NNO. Si and Al are among the slowest-diffusing species in rutile measured thus far. Diffusivities of Al and Si are significantly slower than the diffusion of Pb and slower than the diffusion of tetravalent Zr and Hf and pentavalent Nb and Ta. These data indicate that Al compositional information will be strongly retained in rutile, providing evidence for the robustness of the recently developed Al in rutile thermobarometer. For example, at 900 °C, Al compositional information would be preserved over ~3 Gyr in the center of 250 μm radius rutile grains, but Zr compositional information would be preserved for only about 300 000 yr at this temperature. Al-in-rutile compositions will also be much better preserved during subsolidus thermal events subsequent to crystallization than those for Ti-in-quartz and Zr-in-titanite crystallization thermometers.

scholarly journals Diffusion, Precipitation, and Cavity-Wall Reactions of Ion-Implanted Gold in Silicon

1995 ◽  
Vol 396 ◽  
Author(s):  
S.M. Myers ◽  
G.A. Petersen
Keyword(s):  
Ion Implantation ◽  
Solubility Product ◽  
Rutherford Backscattering Spectrometry ◽  
Rutherford Backscattering ◽  
Cavity Wall ◽  
Temperature Range ◽  
Order Of Magnitude ◽  
Diffusion Precipitation ◽  
Ion Implanted

AbstractThe diffusion of Au in Si and its binding to cavities and to precipitates of the equilibrium Au-Si phase were investigated in the temperature range 1023-1123 K using ion implantation and Rutherford backscattering spectrometry. The diffusivity-solubility product for interstitial Au was found to be about an order of magnitude greater than the extrapolation of previous, indirect determinations at higher temperatures. Chemisorption on cavity walls was shown to be more stable than Au-Si precipitation by 0.1-0.3 eV in the investigated temperature range, indicating that cavities are effective gettering centers for Au impurities.

Point Defects and Diffusion in Ni3Ga

1998 ◽  
Vol 527 ◽  
Author(s):  
T. IKEDA ◽  
A. Almazouzi ◽  
A. Funao ◽  
H. Numakura ◽  
M. Koiwa ◽  
...  
Keyword(s):  
Point Defects ◽  
Positron Lifetime ◽  
Major Element ◽  
Tracer Diffusion ◽  
The Self ◽  
Self Diffusion ◽  
Order Of Magnitude ◽  
Constituent Elements ◽  
Tracer Diffusion Coefficients ◽  
And Diffusion

ABSTRACTThe properties of intrinsic point defects and the self-diffusion behaviour of the constituent elements in Ni3Ga have been studied by positron annihilation, tracer diffusion and interdiffusion experiments. Thermal vacancies have been detected by positron lifetime measurements for specimens quenched from high temperatures. The vacancy formation energy is in the range between 1.7 and 1.8 eV, and is not dependent strongly on the composition. The tracer diffusion coefficients of Ni and Ga are of the same order of magnitude, and the interdiffusion coefficient is about 10 times larger than the diffusion coefficient of Ni. The diffusion in Ni3Ga has been found to satisfy the Darken-Manning equation, as expected from the model of the self-diffusion in this type of materials, where both the species of atoms are assumed to migrate primarily in the sub-lattice of the major element via the ordinary vacancy mechanism.

Self-Diffusion in Liquid Antimony

1977 ◽  
Vol 32 (9) ◽  
pp. 1021-1024 ◽  
Author(s):  
Peter Lamparter ◽  
Siegfried Steeb
Keyword(s):  
Diffusion Coefficient ◽  
Measuring Method ◽  
The Self ◽  
Temperature Range ◽  
Self Diffusion ◽  
Capillary Method ◽  
Self Diffusion Coefficient

AbstractThe diffusion of radioactive Sb in liquid Sb has been measured in the temperature range from 672 °C to 1029 °C by use of the long-capillary method. A measuring method is described by which the sectioning of the specimens can be avoided. The self-diffusion coefficient is represented by the equationD= (5.46 + 0.78) · 10-4 ·exp[- (4230±310)/R T]cm2 sec-1. It is concluded that liquid Sb shows semi-metallic behaviour.

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