ISSN:
1432-0630
Keywords:
61.70
;
78.70
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract By component analyses of positron lifetime spectra in quenched gold, it was found that positrons are strongly trapped by stacking fault tetrahedra (SFT) at which the lifetime is about 160 ps remarkably smaller than that for monovacancies (∼200 ps) or divacancies (∼220 ps). Positron lifetimes at small vacancy clusters were also estimated in relation to the nucleation process of SFT, with the aid of computer simulation of kinetics of vacancy clustering during quenching and on subsequent isochronal annealing. The results show that large atomic relaxation occurs in small vacancy clusters among which pentavacancies have the largest open-space, thereby having the lifetime of about 230 ps larger than that of trior tetra-vacancies (∼160ps). It is also suggested that tetra- and penta-vacancies act as prenuclei for stable nuclei of SFT consisting of six or more vacancies.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00618855
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