Магнитные свойства вакансий и внедренного хрома в кристалле ZnO

The electronic and magnetic properties of ZnO containing Cr doped atoms and Zn and O vacancies in its crystal structure are theoretically investigated. Calculations are performed using Atomistix Tool Kit and Vienna Ab-initio Simulation Package software implementing the electron density functional theory method with the Hubbard correction. It is shown that the magnetic moment of a defect supercell strongly depends on the impurity concentration and presence of vacancies. The doping of an oxygen atom increases the probability of zinc-vacancy formation.

Equilibrium geometries, electronic structure and magnetic properties of ConSn (n = 1–12) clusters from density functional calculations

Equilibrium geometries, relative stabilities, electronic stabilities and magnetic properties of Co[Formula: see text]Sn ([Formula: see text] = 1–12) clusters have been systematically investigated by using relativistic all-electron density functional theory with generalized gradient approximation. The results indicated that the lowest-energy structures of Co[Formula: see text]Sn ([Formula: see text] = 1–5, 7, 9 and 10) clusters are similar to those of corresponding Co[Formula: see text] clusters. As for Co6Sn, Co8Sn, Co[Formula: see text]Sn and Co[Formula: see text]Sn clusters, the most stable structures give rise to a geometry reconstruction. In the low-lying structures of Co[Formula: see text]Sn ([Formula: see text] = 1–12) clusters, tin impurity prefers to occupy the external site. The second-order difference energy of the ground-state Co[Formula: see text]Sn ([Formula: see text] = 1–12) clusters shows a pronounced odd–even oscillation with the number of Co atoms, and the clusters exhibit higher stability at [Formula: see text] = 5. Compared with corresponding pure Co[Formula: see text] clusters, the total magnetic moment of the Co[Formula: see text]Sn clusters reduces with 1, 3 and 5 [Formula: see text], respectively. The different magnetic changes of the tin doped Co clusters are analyzed in detail based on the magnetism coupling, density of state and hybridization between cobalt and tin atoms.

Catalytic activity for oxygen reduction reaction on platinum-based core–shell nanoparticles: all-electron density functional theory

Pt-based core–shell nanoparticles of 55 atoms were subject to analysis of catalytic activity for oxygen reduction reactions.