Magnetic properties of a single vacancy in graphene is a relevant and still unsolved problem. The experimental results point to a clearly detectable magnetic defect state at the Fermi energy, while several calculations based on density functional theory (DFT) yield widely varying results for the magnetic moment, in the range of μ = 1.04 − 2.0 μB . We present a multi-tool ab initio theoretical s...

Based on calculations of activation process parameters for gold, it is shown that if the energy required to create a defect (vacancy or diffusing atom) less than certain value (h i <h si ), resulting has volume (v < v then this negative entropy, i. e. orders crystal. The changes in functions h and with increasing pressure been studied. Keywords: vacancy, self-diffusion, enthalpy, ...

All material supplied via Aaltodoc is protected by copyright and other intellectual property rights, and duplication or sale of all or part of any of the repository collections is not permitted, except that material may be duplicated by you for your research use or educational purposes in electronic or print form. You must obtain permission for any other use. Electronic or print copies may not ...

We have investigated native defects and native defect-impurity complexes as candidate sources for the yellow luminescence in GaN. Using state-of-the-art first-principles calculations, we find strong evidence that the Ga vacancy (VGa) is responsible. The dependence of the VGa formation energy on Fermi level explains why the yellow luminescence is observed only in n-type GaN. The VGa defect level...

Point defects in silicon carbide are rapidly becoming a platform of great interest for single-photon generation, quantum sensing, and quantum information science. Photonic crystal cavities (PCCs) can serve as an efficient light-matter interface both to augment the defect emission and to aid in studying the defects' properties. In this work, we fabricate 1D nanobeam PCCs in 4H-silicon carbide wi...

We provide a new model of the peroxy-radical defect in amorphous silica on the basis of quantum-chemical calculations applied to clusters of atoms to model the defect. In this model, the 29Si hyperfine splittings of the peroxy radical arise from a single silicon, in agreement with the previous experimental findings. Furthermore, we show that the present model of the peroxy radical is consistent...

In non-magnetic RB,, it is shown that the most common defect R vacancy can trap third hole creating a compensating conduction electron due to the narrow gap semiconductor character. The latter is trapped loosely and thus easily causes n-type character. Various transport properties are explained on this model. In magnetic EuB,-, the above defect center makes a giant moment cluster. Furthermore, ...

We study backscattering phenomena during conduction for graphene nanoribbons of mm lengths, from single vacancy scatterers up to finite defect concentrations. Using ab initio calibrated Hamiltonian models we highlight the importance of confinement and geometry on the shaping of the local density of states around the defects that can lead to important alterations on the transport process, giving...