NiBi3 layer growth kinetics

As only the Bi atoms are diffusing and experimental NiBi3 layer thicknesses are large enough, its growth kinetics at the Ni-Bi interface is described by simplified equations (1.32) and (1.33)  

If the layer thickness-time dependence is well described by these equations, then the growth process is undoubtly diffusion controlled. A plot of the layer thickness against the square root of the annealing time is shown in Fig. 1.20. As seen in Fig. 1.20, the experimental points yield three straight lines. Thus, the NiBi3 layer growth is indeed diffusion controlled. 

The experimental values of [l 1ltlcgral at 150, 200 and 250°C are listed in Table 1.4, together with their 0.95 confidence limits. These values represent the volume diffusivities of the Bi atoms in the NiBi 3 lattice in the course of reaction diffusion or, in other words, the reaction-diffusion coefficients of bismuth. The interconnection between the reaction- and self-diffusion coefficients of any component of a chemical compound will be discussed in the next section. 

Note that coincides with A (l4ljl Tcrcntial) only in this particular case, 

The temperature dependence of the reaction-diffusion coefficient (diffusional constant) of bismuth atoms in (or, rather, across) the growing NiBi3 layer is described by the Arrhenius relation (see equation (1.34)). As 

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Growth kinetics of the NiBi3 layer at the nickel-bismuth interface... 

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