Positron annihilation at grain boundaries in metals

Kuriplach, J.; Melikhova, Oksana; Hou, Marc; Petegem, S. Van; Журкин, Е. Е.; Šob, Mojmı́r

doi:10.1002/pssc.200675813

Cited by 6 publications

(2 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the atomistic simulations [76,77] demonstrate, with increasing temperature vacancies become unstable; they delocalize and may lead to instability. Consequently, effective disappearance of the free volume connected with vacancies at temperatures of about 600 K at most may occur.…”

Section: Magnetismmentioning

confidence: 99%

The Effect of Vacancies on Grain Boundary Segregation in Ferromagnetic fcc Ni

et al. 2020

View full text Add to dashboard Cite

This work presents a comprehensive and detailed ab initio study of interactions between the tilt Σ5(210) grain boundary (GB), impurities X (X = Al, Si) and vacancies (Va) in ferromagnetic fcc nickel. To obtain reliable results, two methods of structure relaxation were employed: the automatic full relaxation and the finding of the minimum energy with respect to the lattice dimensions perpendicular to the GB plane and positions of atoms. Both methods provide comparable results. The analyses of the following phenomena are provided: the influence of the lattice defects on structural properties of material such as lattice parameters, the volume per atom, interlayer distances and atomic positions; the energies of formation of particular structures with respect to the standard element reference states; the stabilization/destabilization effects of impurities (in substitutional (s) as well as in tetragonal (iT) and octahedral (iO) interstitial positions) and of vacancies in both the bulk material and material with GBs; a possibility of recombination of Si(i)+Va defect to Si(s) one with respect to the Va position; the total energy of formation of GB and Va; the binding energies between the lattice defects and their combinations; impurity segregation energies and the effect of Va on them; magnetic characteristics in the presence of impurities, vacancies and GBs. As there is very little experimental information on the interaction between impurities, vacancies and GBs in fcc nickel, most of the present results are theoretical predictions, which may motivate future experimental work.

show abstract

Section: Magnetismmentioning

confidence: 99%

The Effect of Vacancies on Grain Boundary Segregation in Ferromagnetic fcc Ni

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Similar interaction between FVs occurs also at grain boundaries as shown in Refs. [15,16]. Understanding how the interaction between defects influences PL and HMP seems to be essential for proper interpretation of the experimental results.…”

Section: Simulation Of Positron Responsementioning

confidence: 99%

Simulation of Positron Annihilation Response to Mechanical Deformation of Nanostructured AgCo

et al. 2008

Self Cite

View full text Add to dashboard Cite

Nanostructured materials attract nowadays a broad attention due to their specific properties. Defects play an essential role in material properties so their characterisation is very important. The evolution of the various open volume defects in AgCo nanowire modelled samples obtained using molecular dynamics was studied. Isothermal and isoenergetic deformation mechanisms are considered. General analyses of open volume defects concerning their size and their chemical environment were performed. Positron lifetimes, binding energies, and high momentum parts of the momentum distribution of annihilation γ-quanta were calculated for selected defects.

show abstract