Room-temperature diffusion coefficients for oxygen and water in UO2 matrices: a SIMS study

2012 ◽  
Vol 45 (1) ◽  
pp. 360-363 ◽  
Author(s):  
I. Marchetti ◽  
P. Carbol ◽  
J. Himbert ◽  
F. Belloni ◽  
T. Fanghänel
Keyword(s):  
Diffusion Coefficients ◽  
Room Temperature ◽  
Temperature Diffusion

scholarly journals Size- and Surface-Dependent Solubility of Cadmium Telluride in Aqueous Solutions

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 398 ◽  
Author(s):  
Renate Zapf-Gottwick ◽  
Matthias Zorn ◽  
Jessica Nover ◽  
Michael Koch ◽  
Carolin Feifel ◽  
...  
Keyword(s):  
Particle Size ◽  
Aqueous Solutions ◽  
Diffusion Coefficients ◽  
Room Temperature ◽  
Ph Value ◽  
Leaching Behavior ◽  
Photovoltaic Modules ◽  
Chemical Treatments ◽  
Temperature Diffusion ◽  
The Stability

Due to the toxicity of cadmium (Cd) and the scarcity of telluride (Te), CdTe-based photovoltaic modules have been under discussion during the last few years. In particular, the stability of CdTe in aqueous solutions is under debate. Here we show that the stability of CdTe depends not only on the pH of water-based solutions but also on size and surface treatment of CdTe particles. We compare milled module pieces with CdTe powders of different particle size. The leaching of CdTe is conditioned by the outdiffusion of Cd and Te at the interface between CdTe particles and the aqueous solution. The smaller the particle size, the faster the leaching. Therefore, milled module pieces decompose faster than CdTe powders with relatively large grains. We observe a dependence on time t according to t0.43. The room temperature diffusion coefficients are calculated as DCd ≈ 3 × 10−17 cm2/s for Cd, and DTe ≈ 1.5 × 10−17 cm2/s for Te in pH4. The chemical instability in aqueous solutions follows thermodynamic considerations. The solution behavior of Cd and Te depends on the pH value and the redox potential of the aqueous solutions. Chemical treatments such as those used in solar cell production modify the surface of the CdTe particles and their leaching behavior.

Room-temperature diffusion in Cu/Ag thin-film couples caused by anodic dissolution

1997 ◽  
Vol 28 (13) ◽  
pp. 843-850 ◽  
Author(s):  
Denny A. Jones ◽  
Alan F. Jankowski ◽  
Gail A. Davidson
Keyword(s):  
Thin Film ◽  
Anodic Dissolution ◽  
Room Temperature ◽  
Temperature Diffusion

Ultra-Shallow Doping of GaAs with Mg, Cr, Mn and B Using Plasma Stimulated Room-Temperature Diffusion

2020 ◽  
Vol 20 (3) ◽  
pp. 1878-1883
Author(s):  
Lei Li ◽  
Ruixiang Hou ◽  
Lili Zhang ◽  
Yihang Chen ◽  
L. Yao ◽  
...  
Keyword(s):  
Room Temperature ◽  
Physical Mechanism ◽  
Plasma Sheath ◽  
Main Role ◽  
External Bias ◽  
Temperature Diffusion ◽  
Plasma Doping ◽  
Order Of Magnitude ◽  
Impurity Ion ◽  
First Time

It is demonstrated that Mg, Cr, Mn and B can be doped close to GaAs surface by plasma doping without external bias at room temperature (RT). The process only takes a few minutes, and impurity densities in the range of 1018–1021/cm3 can be achieved with doping depths about twenty nanometers. The experiment results are analyzed and the physical mechanism is tentatively explained as follows: during the doping process, impurity ion implantation under plasma sheath voltage takes place, simultaneously, plasma stimulates RT diffusion of impurity atom, which plays the main role in the doping process. The enhanced RT diffusion coefficients of Mg, Cr, Mn and B in GaAs are all in the order of magnitude of 10-15 cm2sec-1. This is reported for the first time among all kinds of plasma assisted doping methods.

Low energy boron implantation in silicon and room temperature diffusion

1998 ◽  
Vol 139 (1-4) ◽  
pp. 98-107 ◽  
Author(s):  
E.J.H Collart ◽  
K Weemers ◽  
N.E.B Cowern ◽  
J Politiek ◽  
P.H.L Bancken ◽  
...  
Keyword(s):  
Room Temperature ◽  
Low Energy ◽  
Temperature Diffusion ◽  
Boron Implantation

Measurement of the diffusion coefficients of reactive species in dilute gases

1982 ◽  
Vol 380 (1779) ◽  
pp. 241-258 ◽  
Keyword(s):  
Gas Phase ◽  
Diffusion Coefficients ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Reactive Species ◽  
Resonance Fluorescence ◽  
Hydrogen Atoms ◽  
Chromatographic Effect ◽  
Diffusion Of Hydrogen

A technique has been developed for measuring the diffusion coefficients of atoms and other reactive species in gases below atmospheric pressure. The technique consists of measuring the rate of dispersion of a pulse of reactive species in a stream of gas flowing rapidly ( ca . 10 m s -1 ) down a quartz tube. The reactive species are observed and the profile of the pulses measured by using resonance fluorescence. The technique has been used at room temperature, but in principle measurements could be made at elevated temperatures. Measurements have been made of the rates of diffusion of hydrogen atoms in argon and nitrogen, and values for the diffusion coefficients of 1.61 ± 0.04 and 1.35 ± 0.03 cm 2 s -1 respectively, at 1 atmosphere ( ca . 10 5 Pa) and 294 K, have been obtained. Incidentally to the primary purpose of the experiment, it was observed that the hydrogen atoms spend a small fraction of their time of passage along the tube reversibly adsorbed on its walls. From the measurements, both the partition coefficient, giving the ratio of hydrogen atoms on the walls to those in the gas phase, and the rates of adsorption and desorp­tion can be obtained. This appears to be the first observation of a chromatographic effect for a highly reactive species.

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