Unstable displacement defects and hydrogen trapping in GaAs

1997 ◽  
Vol 56 (7) ◽  
pp. 3813-3819 ◽  
Author(s):  
H. J. Stein ◽  
J. C. Barbour
Keyword(s):  
Hydrogen Trapping ◽  
Unstable Displacement

scholarly journals Evidence of hydrogen trapping at second phase particles in zirconium alloys

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christopher Jones ◽  
Vidur Tuli ◽  
Zaheen Shah ◽  
Mhairi Gass ◽  
Patrick A. Burr ◽  
...  
Keyword(s):  
Density Functional ◽  
Secondary Ion Mass Spectrometry ◽  
Zirconium Alloys ◽  
Nuclear Industry ◽  
Second Phase ◽  
Hydrogen Trapping ◽  
Functional Theory ◽  
Second Phase Particles ◽  
Hydrogen Isotope Ratios ◽  
Dft Modelling

AbstractZirconium alloys are used in safety–critical roles in the nuclear industry and their degradation due to ingress of hydrogen in service is a concern. In this work experimental evidence, supported by density functional theory modelling, shows that the α-Zr matrix surrounding second phase particles acts as a trapping site for hydrogen, which has not been previously reported in zirconium. This is unaccounted for in current models of hydrogen behaviour in Zr alloys and as such could impact development of these models. Zircaloy-2 and Zircaloy-4 samples were corroded at 350 °C in simulated pressurised water reactor coolant before being isotopically spiked with 2H2O in a second autoclave step. The distribution of 2H, Fe and Cr was characterised using nanoscale secondary ion mass spectrometry (NanoSIMS) and high-resolution energy dispersive X-ray spectroscopy. 2H− was found to be concentrated around second phase particles in the α-Zr lattice with peak hydrogen isotope ratios of 2H/1H = 0.018–0.082. DFT modelling confirms that the hydrogen thermodynamically favours sitting in the surrounding zirconium matrix rather than within the second phase particles. Knowledge of this trapping mechanism will inform the development of current understanding of zirconium alloy degradation through-life.

Size-dependent Hydrogen trapping in Palladium nanoparticles

2021 ◽  
Author(s):  
Wang Liu ◽  
Yann Magnin ◽  
Georg Daniel Förster ◽  
Julie Bourgon ◽  
Thomas Len ◽  
...  
Keyword(s):  
Experimental Study ◽  
Theoretical Approach ◽  
Palladium Nanoparticles ◽  
Hydrogen Absorption ◽  
Pd Nanoparticles ◽  
Hydrogen Trapping ◽  
Size Dependent

We report an experimental study, supported by a theoretical approach based on simulations, to explore the phenomenon of H trapping in small Pd nanoparticles. Hydrogen absorption/desorption of a series of...

The Role of Cr in H Desorption Kinetics in Rapidly Solidified Al

2014 ◽  
Vol 783-786 ◽  
pp. 264-269 ◽  
Author(s):  
Iya I. Tashlykova-Bushkevich ◽  
Keitaro Horikawa ◽  
Goroh Itoh
Keyword(s):  
High Temperature ◽  
Thermal Desorption ◽  
High Purity ◽  
Thermal Desorption Spectroscopy ◽  
Secondary Phase ◽  
Hydrogen Desorption ◽  
Oxide Surface ◽  
Desorption Kinetics ◽  
Hydrogen Trapping ◽  
Rapidly Solidified

Hydrogen desorption kinetics for rapidly solidified high purity Al and Al-Cr alloy foils containing 1.0, 1.5 and 3.0 at % Cr were investigated by means of thermal desorption analysis (TDA) at a heating rate of 3.3°C/min. For the first time, it was found that oxide inclusions of Al2O3 are dominant high-temperature hydrogen traps compared with pores and secondary phase precipitates resulted in rapid solidification of Al and its alloys. The correspondent high-temperature evolution rate peak was identified to be positioned at 600°C for high purity Al and shifted to 630°C for Al-Cr alloys. Amount of hydrogen trapped by dislocations increases in the alloys depending on Cr content. Microstructural hydrogen trapping behaviour in low-and intermediate temperature regions observed here was in coincidence with previous data obtained for RS materials using thermal desorption spectroscopy (TDS). The present results on hydrogen thermal desorption evolution indicate that the effect of oxide surface layers becomes remarkable in TDA measurements and show advantages in combinations of both desorption analysis methods to investigate hydrogen desorption kinetics in materials.

Hydrogen Transport in 34CrMo4 Martensitic Steel: Influence of Microstructural Defects on H Diffusion

2012 ◽  
Vol 323-325 ◽  
pp. 485-490 ◽  
Author(s):  
L. Moli-Sanchez ◽  
F. Martin ◽  
E. Leunis ◽  
J. Chêne ◽  
M. Wery
Keyword(s):  
Diffusion Coefficient ◽  
Room Temperature ◽  
Martensitic Steel ◽  
Hydrogen Trapping ◽  
Martensitic Steels ◽  
Hydrogen Diffusivity ◽  
Apparent Diffusion ◽  
Quenched Steel ◽  
Set Up ◽  
Permeation Test

The electrochemical permeation technique was used to evaluate the effect of the microstructure on hydrogen diffusivity and hydrogen trapping at room temperature in martensitic steels. A detailed study of the electrochemical permeation technique was first performed in order to identify the boundary conditions of a permeation test in the selected experimental set-up. The validity of the apparent diffusion coefficient derived from this test is also discussed. A 34CrMo4 quenched steel has been selected and designed at three tempering temperatures (200°C, 540°C and 680°C) in order to obtain three different microstructures. According to permeation measurements, H diffusion strongly depends on the microstructure. The material tempered at 540°C exhibits the smallest diffusion coefficient and the largest fraction of reversible traps at room temperature.

Effect of precipitate coherency on the corrosion-induced hydrogen trapping in 2024 aluminum alloy

2021 ◽  
Vol 46 (69) ◽  
pp. 34487-34497
Author(s):  
H. Kamoutsi ◽  
G.N. Haidemenopoulos ◽  
H. Mavros ◽  
C. Karantonidis ◽  
P. Floratos ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Hydrogen Trapping ◽  
2024 Aluminum Alloy

Hydrogen trapping at dislocation cores at room temperature in deformed Pd

2013 ◽  
Vol 577 ◽  
pp. 189-191 ◽  
Author(s):  
Brent J. Heuser ◽  
Dallas R. Trinkle ◽  
Tai-Ni Yang ◽  
Lilin He
Keyword(s):  
Room Temperature ◽  
Hydrogen Trapping
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