The Characterization of Proton Irradiated BaSrFBr:Eu Film by the Coincidence Doppler Broadening Positron Annihilation Spectroscopy

Positron annihilation spectroscopy using lifetime and Doppler broadening allows the characterization of the lithiation state in LiCoO2 thin film used in cathode of lithium-ion batteries. The lifetime results reflect positron spillover because of the presence of graphite in between the oxide grains in real cathode Li-ion batteries. This spillover produces an effect in the measured positron parameters which are sensitive to delocalized electrons from lithium atoms as in Compton scattering results. The first component of the positron lifetime corresponds to a bulk-like state and can be used to characterize the state of charge of the cathode while the second component represents a surface state at the grain-graphite interface.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.1132 ◽

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.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.519-521.309 ◽

2006 ◽

Vol 519-521 ◽

pp. 309-314 ◽

Cited By ~ 6

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.

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