Near-surface defects

Eqn (2.92) is the culmination of our efforts to compute the displacements due to an arbitrary distribution of body forces. Although this result will be of paramount importance in coming chapters, it is also important to acknowledge its limitations. First, we have assumed that the medium of interest is isotropic. Further refinements are necessary to recast this result in a form that is appropriate for anisotropic elastic solids. A detailed accounting of the anisotropic results is spelled out in Bacon et al. (1979). The second key limitation of our result is the fact that it was founded upon the assumption that the body of interest is infinite in extent. On the other hand, there are a variety of problems in which we will be interested in the presence of defects near surfaces and for which the half-space Green function will be needed. Yet another problem with our analysis is the assumption that the elastic constants... 

Shearography monitors the speckular 2D interference pattern of an unpolished surface illuminated by a coherent light source, and is therefore a metliod that lends itself to the testing of industrial materials. Small surface, or near-surface defects may produce localised strain on... 

Fig. 7. Bombardment processes at the surface and in the near-surface region of a sputtering target, where represents the energetic particle used for bombarding the surface <), an adsorbed surface species 0> atoms and x, lattice defects.

Apart from its role in interacting with existing defects and impurities, hydrogen has recently been shown to induce defects as well (Johnson et al., 1987). Extended defects (described as platelets ) in the near-surface region were observed after hydrogenation and correlated with the presence of large concentrations of H. Theoretical models will be discussed in Part VIII. Part IX, finally, will contain some conclusions and point out directions for future work. As is the case for so many other topics in semiconductor physics, silicon (Si) has been the material for which the majority of... 

A surface peak effect has been observed during Rb and Sr diffusion in vitreous silica (13). Such large near-surface concentrations are postulated to result from the exposure at the glass surface of a greater number of interstices or defects over which diffusion can occur. This would lead to steep penetration curves observed in some XPS profiles of glass. 

A general feature of doped semiconductive NC materials is described in a review paper authored by Bhargava, one of the founders of this area (8). It is generally accepted that solid particles are richer in crystallographical defects when their diameter becomes smaller. Quantum size effects associated with nanoparticles are very sensitive to the defects. In most cases, defects influence negatively the luminescent properties of phosphors. Most of these drawbacks of NC phosphors are attributed to the larger specific surface area, since defects tend to concentrate themselves in a near-surface region. 

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