ﻻ يوجد ملخص باللغة العربية
The electronic structures of Sn and Pb implanted SiO2 are studied using soft X-ray absorption (XAS) and emission (XES) spectroscopy. We show, using reference compounds and ab initio calculations, that the presence of Pb-O and Sn-O interactions can be detected in the pre-edge region of the oxygen K-edge XAS. Via analysis of this interaction-sensitive pre-edge region, we find that Pb implantation results primarily in the clustering of Pb atoms. Conversely, with Sn implantation using identical conditions, strong Sn-O interactions are present, showing that Sn is coordinated with oxygen. The varying results between the two ion types are explained using both ballistic considerations and density functional theory calculations. We find that the substitution of Pb into Si sites in SiO2 requires much more energy than substituting Sn in these same sites, primarily due to the larger size of the Pb ions. From these calculated formation energies it is evident that Pb requires far higher temperatures than Sn to be soluble in SiO2. These results help explain the complex processes which take place upon implantation and determine the final products.
Investigations within the local spin density functional theory (LSDF) of the intermetallic hydride system $ {rm CeRhSnH_x} $ were carried out for discrete model compositions in the range $ 0.33 leq x_H leq 1.33 $. The aim of this study is to assess t
The results of XPS core-level and valence band measurements, photoluminescence spectra of a-SiO2 implanted by Zn-ions (E=30 keV, D=1*1017 cm^-2) and Density Functional Theory calculations of electronic structure as well as formation energies of struc
The results of studies of supercooling upon crystallization value of Bi, Sn and Pb nanosized particles on the Al substrate and between the Al layers have been presented. It has been shown the efficiency of usage of layered film systems for investigat
We address the role of Sn-substitution and Pb-vacancy (Pb-$Box$) in regulating stability and carrier concentration of CH$_3$NH$_3$Pb$_{1-X-Y}$Sn$_X$$Box_Y$I$_3$ perovskite using density functional theory, where the performance of the exchange-correla
The recent discovery of a topological phase transition in IV-VI narrow-gap semiconductors has revitalized the decades-old interest in the bulk band inversion occurring in these materials. Here we systematically study the (001) surface states of Pb{1-