Palakkal Asoka-Kumar

TL;DR: In this article, the positron annihilation spectroscopy (PAS) was used as a non-destructive probe to examine defects in technologically important Si-based structures, including the quality of overlayers, formation and annealing of defects after ion implantation, identification of defect complexes, and evaluation of the distribution of internal electric fields.

TL;DR: In this article, the effect of dc current on the annealing of point defects in Ni3Ti was investigated by positron annihilation spectroscopy, and the results were interpreted in terms of the electron wind effect and the complex nature of diffusion in ordered intermetallic phases.

TL;DR: In this article, Positron annihilation spectroscopy was employed to study free volume in a Zr-Ti-Ni-Cu-Be bulk metallic glass following plastic straining and cathodic charging with atomic hydrogen.

TL;DR: In this article, the free volume changes associated with inhomogeneous plastic deformation of a Cu-based bulk metallic glass were examined using positron annihilation spectroscopy (PAS), and the results indicated that there was a distribution of free volume site sizes in both the as-quenched and rolled glasses, and that the concentration of larger sites increased with deformation.

TL;DR: In situ depth-resolved positron annihilation spectroscopy (PAS) is used to show dynamic formation of vacancies in 1 μm×1 μm Al−0.5 wt% Cu lines under current flow as discussed by the authors.