Boundary thickness

L = average grain diameter S = grain boundary thickness... 

In order to determine the grain boundary thickness, C2-values have to be analyzed according to Eq. (44). As for R2, the specific geometry of the investigated grain boundary and its surroundings affects the analysis since only estimates of the grain boundary area and the /c-factor are available. Hence, a relatively broad distribution... 

The non-diamond carbon phase in polycrystalline diamond films (often referred to as graphite, although this conclusion is far from accurate [23]) is first and foremost the disordered carbon in the intercrystallite boundaries. Their exposure to the film surface can be visualized by using a high-resolution SEM techniques [24] the intercrystallite boundaries thickness comes to a few nanometers. In addition to the intercrystallite boundaries, various defects in the diamond crystal lattice contribute to the non-diamond carbon phase, not to mention a thin (a few nanometers in thickness) amorphous carbon layer on top of diamond. This layer would form during the latest, poorly controlled stage of the diamond deposition process, when the gas phase activation has ceased. The non-diamond layer affects the diamond surface conduc-... 

Using these equations, the numerical procedure outlined above can be used to find the variation of the local heat transfer rate in the form of Nup/Pe 2 around the cylinder. The solution procedure does not really apply near the rear stagnation point (R in Fig. 10.17) because the effective boundary thickness becomes very large in this area as indicated in Fig. 10.17. This is however, of little practical importance because the heat transfer rate is very low in the region of the rear stagnation point. 

In common cases, the grain-boundary thickness is close to a few nanometers the overall volume fraction of the boundaries is very small. The opposite situation is observed in nano crystalline solids, with profound effects on defect - thermodynamics and transport. 

From Eqn. (5) we see that the important intrinsic variables controlling creep are the boundary thickness, w, the grain size, d, and the viscosity of the boundary fluid, tj. If these parameters change in the course of the deformation process, a corresponding change in the creep rate will occur, leading to transient creep behavior. 

Koberstein J. T., Morra B. and Stein R. S., The determination of diffuse-boundary thickness of polymers by small angle X-ray scattering. J. Appl. Cryst. 13(1980) pp. 34-45. 

Budai, J., Gaudig, W., Sass, S. L. (1979). Measurement of grain boundary thickness using x-ray diffraction techniques. Phil. Mag., 39, 533-49. 

Maimed and Klein [6.20] found two-dimensional defects (probably cluster boundaries) in the quasi-crystal Al Mn. The sizes of clusters (quasi-crystallites) comprise 102u, and the boundary thickness equals approximately a. 

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