Related papers: Cs diffusion in SiC high-energy grain boundaries
Energetics of Cs defects at Sigma3 grain boundaries of 3C-SiC has been studied using density functional theory to understand the role of the grain boundaries in Cs diffusion and its eventual release from the tristructural isotropic fuel…
Silver released from TRISO fuel particles can migrate through the SiC layer and deposit on reactor components, posing radiation hazards and operational challenges. Despite numerous proposed mechanisms, the precise pathway of silver…
New SiS multi-transition (sub-)millimetre line observations of a sample of AGB stars with varying photospheric C/O-ratios and mass-loss rates are presented. A combination of low- and high-energy lines are important in constraining the…
We investigate the formation of silicon carbide (SiC) grains in the framework of dust-driven wind around pulsating carbon-rich Asymptotic Giant Branch (C-rich AGB) stars in order to reveal not only the amount but also the size distribution.…
Presolar silicon carbide (SiC) grains in meteoritic samples can help constrain circumstellar condensation processes and conditions in C-rich stars and core-collapse supernovae. This study presents our findings on eight presolar SiC grains…
One of the main challenges in the study of TRISO (Tristructural Isotropic) coated fuel particles is the understanding of the diffusion of fission products through SiC. Among the elements produced inside the uranium kernel, it has been…
SiC materials are potential plasma facing materials in fusion reactors. In this study, site preference and diffusion behaviors of H in pure 3C-\b{eta} SiC and in He-implanted 3C-\b{eta} SiC are investigated, on the basis of the…
Aim: We aim to determine the abundances of CS, SiO, and SiS in a large sample of carbon star envelopes covering a wide range of mass loss rates to investigate the potential role that these molecules could play in the formation of dust in…
New SiO multi-transition millimetre line observations of a sample of carbon stars, including J=8-7 observations with the APEX telescope, are used to probe the role of non-equilibrium chemistry and the influence of grains in circumstellar…
Understanding hydrogen-grain boundary (GB) interactions is critical to the analysis of hydrogen embrittlement in metals. This work presents a mesoscale fully kinetic model to investigate the effect of GB misorientation on hydrogen diffusion…
We have mapped the J=1-0 line of SiO in a 1 degree x 12 arcmin. (lxb) region around the Galactic center (GC) with an angular resolution of 2 arcmin. (approx. 4 pc). In contrast to the spatial distribution of other high dipole moment…
The spatial distribution of molecules in AGB circumstellar envelopes is regulated by different processes. In the outer layers all molecules are destroyed due to the interaction with interstellar ultraviolet photons. Here we aim to…
Aims: We aim to determine the abundances of SiO, CS, SiS, SO, and SO$_2$ in a large sample of oxygen-rich AGB envelopes covering a wide range of mass loss rates to investigate the potential role that these molecules could play in the…
We report the first detection of SiC$_2$ in the interstellar medium. The molecule was identified through six rotational transitions toward G\,+0.693$-$0.027, a molecular cloud located in the Galactic center. The detection is based on a line…
We have studied diffusion pathways of a silyl radical adsorbed on the hydrogenated Si (100)-(2x1) surface by density-functional theory. The process is of interest for the growth of crystalline silicon by plasma-enhanced chemical vapor…
Hydrogen embrittlement remains a critical challenge in structural and electronic applications of copper (Cu) but its mechanism is still not fully understood. In this study, we combine density functional theory (DFT) and bond-order potential…
The circumgalactic medium (CGM) is poorly constrained at the sub-parsec scales relevant to turbulent energy dissipation and regulation of multi-phase structure. Fast radio bursts (FRBs) are sensitive to small-scale plasma density…
The study of the gas in the envelopes surrounding asymptotic giant branch (AGB) stars through observations in the millimetre wavelength range provides information about the history and nature of these molecular factories. Here we present…
We reveal the microscopic self-diffusion process of compact tri-interstitials in silicon using a combination of molecular dynamics and nudged elastic band methods. We find that the compact tri-interstitial moves by a collective…
The diffusion of intrinsic defects in 3C-SiC is studied using an ab initio method based on density functional theory. The vacancies are shown to migrate on their own sublattice. The carbon split-interstitials and the two relevant silicon…