Vacancy Clusters in Irradiated Metals Studied by Positron Annihilation Technique

Positron annihilation radiation Doppler broadening spectroscopy was used to study defects in semi-insulating (SI) silicon carbide (SiC) substrates grown by high-temperature chemical vapour deposition (HTCVD). The Doppler broadening measurements show (i) that the measured samples contain vacancy clusters (ii) that the positron trapping to the clusters is increased in annealing (iii) that the chemical environment of the defects in the un-annealed samples is different from those of the annealed samples.

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Positron Annihilation in Ion-Implanted ZnO

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.295-296.1 ◽

2010 ◽

Vol 295-296 ◽

pp. 1-10

Author(s):

Aman Deep Acharya ◽

Girjesh Singh ◽

S.B. Shrivastava

Keyword(s):

Positron Annihilation ◽

Atomic Number ◽

Zno Films ◽

Doppler Broadening ◽

Vacancy Clusters ◽

S Parameter ◽

Trapping Model ◽

Ion Implanted

The Diffusion Trapping Model has been used to obtain the positron annihilation Doppler broadening lineshape parameter in ZnO and O+, B+, N+, Al+ implanted ZnO films. The concentration of vacancy clusters is found to be related to the atomic number and the fluence of the implanted ion. The S-parameter is found to be largest in the case of implantation of Al+ ions and is minimum for the implantation of B+ ions. Thus, the vacancy clusters are found to be largest in the case of Al+ implantation. The calculated results have been compared with the experimental value.

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On the possibility of the positron annihilation method to detect vacancy clusters in shock-loaded metals

Journal of Mechanical Working Technology ◽

10.1016/0378-3804(87)90035-0 ◽

1987 ◽

Vol 15 (2) ◽

pp. 215-227 ◽

Cited By ~ 1

Author(s):

N.M. Nancheva

Keyword(s):

Positron Annihilation ◽

Vacancy Clusters

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Evolution and role of vacancy clusters at grain boundaries of ZnO:Al during accelerated degradation of Cu(In,Ga)Se2 solar cells revealed by positron annihilation

Physical Review Materials ◽

10.1103/physrevmaterials.2.105403 ◽

2018 ◽

Vol 2 (10) ◽

Cited By ~ 2

Author(s):

Wenqin Shi ◽

Mirjam Theelen ◽

Andrea Illiberi ◽

Nicolas Barreau ◽

Stefan J. van der Sar ◽

...

Keyword(s):

Solar Cells ◽

Grain Boundaries ◽

Positron Annihilation ◽

Vacancy Clusters ◽

Accelerated Degradation

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Change in the Positron Annihilation Lifetime of Vacancy Clusters Containing Hydrogen Atoms in Electron-Irradiated F82H

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1024.71 ◽

2021 ◽

Vol 1024 ◽

pp. 71-78

Author(s):

Koichi Sato ◽

Yohei Kondo ◽

Masakiyo Ohta ◽

Qiu Xu ◽

Atsushi Yabuuchi ◽

...

Keyword(s):

Theoretical Calculation ◽

Positron Annihilation ◽

Room Temperature ◽

Vacancy Cluster ◽

Hydrogen Atoms ◽

Positron Annihilation Lifetime ◽

Vacancy Clusters ◽

Hydrogen Charging ◽

Trapping Effect ◽

Before And After

The change in the positron annihilation lifetime (PAL) of vacancy clusters before and after electrolysis hydrogen charging was determined using PAL measurements in electron-irradiated F82H. The experimental change indicated 8 hydrogen atoms were trapped in vacancy clusters; whereas the theoretical calculation resulted in approximately 14 atoms. As the samples were left at room temperature for 5 min until the start of the PAL measurements, the de-trapping effect of hydrogen atoms was also considered; approximately 13 hydrogen atoms were captured at each vacancy cluster. The PAL decreased after annealing at 148 K, which could not be explained theoretically. Therefore, further experiments and discussions are needed to obtain a precise change in the PAL of vacancy clusters containing hydrogen atoms in F82H.

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