Some Comparisons of Ag Deposits on Ge and Si(111)

Abstract

Crystal growth and surface diffusion have been studied in the Ag/Ge(lll) system using UHV-SEM based techniques, biassed secondary electron imaging (b-SEI), micro-AES and RHEED. Ag was deposited through and past a mask of holes held close to the substrate at 300<Td< 775K. Under certain conditions, the Ag patches were observed to split into two regions corresponding to the √3×√3R30° (hereafter √3) and a lower coverage 4×4 structure, each of which were easily observable using b-SEI. These patch widths were measured as a function of Td, and of annealing times at temperatures Ta, and effective diffusion coefficents extracted. The diffusion length of adatoms over the 4×4 structure is larger than that over the √3 structure. These observations are modelled using kinetic rate equations, and the results are compared with previous studies of Ag/Si(111). We find that energies characterising processes on top of the √3 layers of both systems are very similar, but that processes involved in the formation of the layers are quite different. The coverage of the √3 Ag/Ge(111) layer is close to 1 ML for all Td studied, unlike √3 Ag/Si(111). where it depends on deposition and annealing conditions.

Effect of silane coupling agent on mechanical performance of glass fibre

“…It has been reported that the tensile strength of boron-free virgin E-glass fibres lies in the range from 3.1 to 3.8 GPa [2]. The reduced strength (below the pristine value) is generally considered to be a manifestation of surface flaws existing on the tested samples [20,21]. Since both samples have experienced an identical production, mechanical handling, and environmental history before testing, the results in Fig.…”