Vacancy-mediated climb models cannot account for the fast, direct coalescence of dislocation loops seen experimentally. An alternative mechanism, self climb, allows prismatic dislocation loops to move away from their glide surface via pipe diffusion around the loop perimeter, independent of any vacancy atmosphere. Despite the known importance of self climb, theoretical models require a typicall...

We provide the explanation of the large discrepancy of three orders of magnitude between the experimentally measured and theoretically calculated magnetic moments in ZnS nanocrystals. We assume that the condensation of Zn vacancies into a single droplet takes place. The energy calculations reveal that the droplet phase is more favorable than the uniformly distributed vacancy configuration. The ...

The interaction of fullerenes with transition metal surfaces leads to the development of an atomic network of ordered vacancies on the metal. However, the structure and formation mechanism of this intricate surface reconstruction is not yet understood at an atomic level. We combine scanning tunneling microscopy, high resolution and temperature programmed-x-ray photoelectrons spectroscopy, and d...

The formation and distribution of oxygen vacancy in layered multicomponent InAMO4 oxides withA3+ = Al or Ga andM2+ = Ca or Zn and in the corresponding binary oxide constituents is investigated using first-principles density functional calculations. Comparing the calculated formation energies of the oxygen defect at six different site locations within the structurally and chemically distinct lay...

The combination of growing demand for long-term care and higher expectations of care staff needs to be set in the context of long-standing concerns about the sustainability of recruitment and retention of front-line staff in the United Kingdom. Organisational and work environment factors are associated with vacancy levels and turnover rates. The aim of the current analysis was to investigate ch...

Grain boundary motion may be accompanied with vacancy generation [1–4]. A typical case where a moving grain boundary produces vacancies is in primary recrystallisation, when the growth of a recrystallised grain at the cost of a grain with a large dislocation density involves release of excess free volume. Vacancies are also generated during grain growth, when the total volume of the grain bound...

A seminal milestone in lattice statistics is the exact solution of the enumeration of dimers on a simple-quartic net obtained by Fisher, Kasteleyn, and Temperley (FKT) in 1961. An outstanding related and yet unsolved problem is the enumeration of dimers on a net with vacant sites. Here we consider this vacant-site problem with a single vacancy occurring at certain specific sites on the boundary...

In the present work, the behavior of He in the MAX phase Ti3AlC2 material is investigated using first-principle methods. It is found that, according to the predicted formation energies, a single He atom favors residing near the Al plane in Ti3AlC2. The results also show that Al vacancies are better able to trap He atoms than either Ti or C vacancies. The formation energies for the secondary vac...

The development of hybrid quantum systems is central to the advancement of emerging quantum technologies, including quantum information science and quantum-assisted sensing. The recent demonstration of high-quality single-crystal diamond resonators has led to significant interest in a hybrid system consisting of nitrogen-vacancy centre spins that interact with the resonant phonon modes of a mac...

Fig. 2 Average binding energy of Pt for 71 different Pt nanostructures on the TiN(100) surface with different concentrations of surface N or Ti vacancies (xv), which refers to the number of vacancies per possible vacancy sites. (a) The average binding energy per Pt atom, as calculated according to eqn (1), versus Pt surface coverage (Y) for up to 3 adlayers (36 Pt atoms) of Pt on the clean TiN(...