相关论文: Diffusion-reaction mechanisms of nitriding species…

We study using first-principles calculations the energetics, structural and electronic properties of nitrogen incorporation in SiO2. We consider NO, NH, N2 and atomic N as the nitriding species interacting with a Si-Si bond of an otherwise…

The thermal growth of silicon oxide films on Si in dry O2 is modelled as a dynamical system, assuming that it is basically a diffusion-reaction phenomenon. Relevant findings of the last decade are incorporated, as structure and composition…

Although Ti2N and Ti belong to different crystal systems and Bravais lattices, we show that N intercalation in Hexagonal Close-Packed (HCP) Ti can lead to the formation of Ti2N by diffusionless displacement of Ti atoms, which is a…

Atomistic computer simulations are applied to investigate the atomic structure, thermal stability, and diffusion processes in Al-Si interphase boundaries as a prototype of metal-ceramic interfaces in composite materials. Some of the most…

Hole formation in a polycrystalline Ni film on an $\alpha$-Al$_2$O$_3$ substrate coupled with a continuum diffusion analysis demonstrates that Ni diffusion along the Ni/$\alpha$-Al$_2$O$_3$ interface is surprisingly fast. Ab initio…

The diffusion of atoms and radicals on interstellar dust grains is a fundamental ingredient for predicting accurate molecular abundances in astronomical environments. Quantitative values of diffusivity and diffusion barriers usually rely…

At the low temperatures of interstellar dust grains, it is well established that surface chemistry proceeds via diffusive mechanisms of H atoms weakly bound (physisorbed) to the surface. Until recently, however, it was unknown whether atoms…

The amorphous aluminium silicate (Al2O3)2(SiO2) [AS2] is investigated by means of large scale molecular dynamics computer simulations. We consider fully equilibrated melts in the temperature range 6100K >= T >= 2300K as well as glass…

The formation of Ni(Pt)silicides on a Si(001) surface is investigated using an ab initio approach. After deposition of a Ni overlayer alloyed with Pt, the calculations reveal fast diffusion of Ni atoms into the Si lattice, which leads…

Diffusion involving atom transport from one location to another governs many important processes and behaviors such as precipitation and phase nucleation. Local chemical complexity in compositionally complex alloys poses challenges for…

Using a large scale molecular dynamics computer simulation we investigate the dynamics of a supercooled melt of SiO_2. We find that with increasing temperature the temperature dependence of the diffusion constants crosses over from an…

Molecular dynamics simulation of Al/Ni multilayered foils reveals a range of different reaction pathways depending on the temperature of the reaction. At the highest temperatures Fickian interdiffusion dominates the intermixing process. At…

"Hot atoms", which are atoms in their excited states, transfer their energy to the surrounding atmosphere through collisions. This process of energy transfer is known as thermalization, and it plays a crucial role in various astrophysical…

While reversibility is a fundamental concept in thermodynamics, most reactions are not readily reversible, especially in solid state physics. For example, thermal diffusion is a widely known concept, used among others to inject dopant atoms…

We present polarised-neutron diffraction measurements of the Ising-like spin-chain compound Ca3Co2O6 above and below the magnetic ordering temperature TN. Below TN, a clear evolution from a single-phase spin-density wave (SDW) structure to…

Nearly one third of all nitrogen oxides are removed from the atmosphere through the reactive uptake of N$_2$O$_5$ into aqueous aerosol. The primary step in reactive uptake is the rapid hydrolysis of N$_2$O$_5$, yet despite significant…

We study the discrete Gierer-Meinhardt model of reaction-diffusion on three different types of networks: regular, random and scale-free. The model dynamics lead to the formation of stationary Turing patterns in the steady state in certain…

We report a detailed neutron scattering study of the ordering of spins and holes in oxygen-doped La(2)NiO(4.133). The single-crystal sample exhibits the same oxygen-interstitial order but better defined charge-stripe order than that studied…

We have studied the physical properties of Nd$_2$O$_3$ with neutron diffraction, inelastic neutron scattering, heat capacity, and magnetic susceptibility measurements. Nd$_2$O$_3$ crystallizes in a trigonal structure, with Nd$^{3+}$ ions…

We have used a combination of density functional theory (DFT) and kinetic Monte Carlo (KMC) simulations to calculate the reaction rates for the selective oxidation of ammonia on RuO2(110). We find that the overall energy barrier for NH3 + O…