Yasuharu Shirai

TL;DR: Positron lifetime spectroscopy was applied to examine the synergistic effect of hydrogen and plastic straining on the vacancy generation in iron as discussed by the authors, showing that the presence of hydrogen enhances the generation of vacancies, rather than of dislocations.

TL;DR: NEXAFS analysis and first-principles calculations are used to study the local environments of Ga dopants at levels of 10 p.p.m in otherwise high-purity MgO to provide a general method of identifying the defect states of ultradilute dopants in ceramics.

TL;DR: In this article, the positron lifetime spectroscopy was used to characterize AB5 and AB2 hydrogen storage compounds by using positron-annihilation lifetime spectrograms and showed that they contain no constitutional vacancies and that deviations from the stoichiometric compositions are all compensated by antistructure atoms.

TL;DR: In this article, a comparison of positron annihilation lifetime measurements using synthetic fused silica and polycarbonate was conducted with the participation of 12 laboratories and the uncertainties of the positron lifetimes obtained at different laboratories were significantly reduced in comparison with those reported in the past.

TL;DR: In this paper, the positron lifetime spectra were analyzed to show that a surprising amount of vacancies together with dislocations are generated by the hydriding at room temperature.