scholarly journals Proton Irradiated Cz-Si by the Coincidence Doppler Broadening Positron Annihilation Spectroscopy

2011 ◽  
Vol 20 (5) ◽  
pp. 367-373 ◽  
Author(s):  
K.H. Lee ◽  
C.Y. Lee
Keyword(s):  
Positron Annihilation ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Coincidence Doppler Broadening

Influence of Nb and Sn on d Electrons of TiAl Alloys Studied by Coincidence Positron Annihilation Spectroscopy

2011 ◽  
Vol 415-417 ◽  
pp. 1132-1135
Author(s):  
Juan Gao ◽  
Jing Ying Ye ◽  
Wen Chun Zhang ◽  
Hui Juan Wang ◽  
Wen Deng
Keyword(s):  
Single Crystals ◽  
Positron Annihilation ◽  
Tial Alloy ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Tial Alloys ◽  
3D Electron ◽  
Doppler Broadening Spectra ◽  
Coincidence Doppler Broadening

The coincidence Doppler broadening spectra of single crystals of Si, Al, polycrystals of Ti, Nb and Sn, and TiAl-based alloys (TiAl, Ti50Al48Nb2and Ti50Al48Sn2) have been measured and analyzed. It has been found that the 3d electron signal for binary TiAl alloy is lower than expected due to the Ti 3d-Al 3p interactions. The addition of Nb atoms to TiAl alloy leads to the enhancement of d-d interactions and thus the d electron signal in the spectrum. The d electron signal in the spectrum of Ti50Al48Nb2alloy is higher than that of Ti50Al48Sn2alloy. The influence of Nb and Sn on d electrons of TiAl alloys has been discussed.

Vacancy-Solute Aggregates in Al-Zn-Mg-(Cu, Ag)

2006 ◽  
Vol 519-521 ◽  
pp. 309-314 ◽  
Author(s):  
Rafael Ferragut ◽  
A. Dupasquier ◽  
M.M. Iglesias ◽  
C.E. Macchi ◽  
Alberto Somoza ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Strong Interaction ◽  
Positron Annihilation Spectroscopy ◽  
The Other ◽  
Alloying Elements ◽  
Artificial Ageing ◽  
Doppler Broadening ◽  
Coincidence Doppler Broadening

Positron annihilation spectroscopy in two versions (lifetime and coincidence Doppler broadening) has been applied to investigate solute/vacancy interactions when minor amounts (<1wt.%) of Ag or Cu are added to the alloy Al-4Zn-3Mg (wt.%) during ageing at 150°C. The results show early clustering of vacancies with Zn (and with Cu, if present). Ag displays a strong interaction with vacancies in competition with Mg and forms clusters that may help further aggregation of the other alloying elements during artificial ageing. High Mg concentration is observed at the misfit interfaces of semi-coherent or incoherent precipitates.

Annihilation Lifetime Spectroscopy Using Positrons from Bremsstrahlung Production

2012 ◽  
Vol 331 ◽  
pp. 41-52 ◽  
Author(s):  
Andreas Wagner ◽  
Wolfgang Anwand ◽  
Maik Butterling ◽  
Thomas E. Cowan ◽  
Fine Fiedler ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Linear Accelerator ◽  
Electron Accelerator ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Electron Linear Accelerator ◽  
Positron Annihilation Lifetime ◽  
Electron Bremsstrahlung ◽  
New Type ◽  
Set Up

A new type of a positron annihilation lifetime spectroscopy (PALS) system has been set up at the superconducting electron accelerator ELBE [ at Helmholtz-Zentrum Dresden-Rossendorf. In contrast to existing source-based PALS systems, the approach described here makes use of an intense photon beam from electron bremsstrahlung which converts through pair production into positrons inside the sample under study. The article focusses on the production of intense bremsstrahlung using a superconducting electron linear accelerator, the production of positrons inside the sample under study, the efficient detector setup which allows for annihilation lifetime and Doppler-broadening spectroscopy simultaneously. Selected examples of positron annihilation spectroscopy are presented.

The Evolution Behavior of Defects in the Nanofilms of W/Cu and W Probed by Doppler Broadening Positron Annihilation Spectroscopy

2017 ◽  
Vol 373 ◽  
pp. 104-107
Author(s):  
Ling Wang ◽  
Ai Hong Deng ◽  
Kang Wang ◽  
Yong Wang ◽  
Xiao Bo Lu ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Positron Annihilation ◽  
Room Temperature ◽  
Storage Time ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Radio Frequency Magnetron Sputtering ◽  
Helium Ions ◽  
Near Surface ◽  
Evolution Behavior

W/Cu multilayer nanofilms and pure W nanofilms were prepared in pure Ar and He/Ar mixing atmosphere by radio frequency magnetron sputtering method. The defect evolution of the samples was characterized by Doppler broadening positron annihilation spectroscopy (DB-PAS).The results show that plenty of defects can be produced by introducing helium (He) into W/Cu multilayer nanofilms. With the natural storage time increasing, the helium located in the near surface of W/Cu multilayer nanofilm would be released gradually and induce the coalescence of the helium related defects due to the diffusion of the helium and defects. In addition, the pure W nanofilms were irradiated by 30 keV helium ions and 40 keV hydrogen (H) ions in sequence at room temperature. From the DB-PAS analysis, it can be shown that a large number of vacancy-type defects are produced due to the He and/or H irradiation. H ions would be trapped by He related defects and produced He-H-V complexes.

Sign in / Sign up

Export Citation Format

Share Document