Structure transformation film morphology

There are two basic problems in activation of inert substrates by electrodeposition first, the effect of the structure of the active surface film on the transformation of electrode from inert to active one7 and second, effect of the surface morphology on the polarization characteristics of activated electrodes.8,9 Obviously, in the last case, the nature of the initial substrate is not important. The analysis of both of them is the aim of this chapter. It will be performed for the cathodic reactions. Obviously, the corresponding analysis for the anodic processes can be performed in the similar way. 

For any surface morphologies to appear, a surface reconstruction mechanism is required that would transform initially planar surface into a structured one. In epitaxially grown solid films such mechanism is surface diffusion in which atoms jump along the surface from one site to another, driven by the gradient of the surface chemical potential. The surface flux of atoms, j, is given by the analog of the Pick s law js = —MVsPs, where ps is the sur-... 

Fig. 5.26 The AFM images (recorded in tapping mode) evidenced the morphological changes on the local nanostructure by annealing the film to water vapor. The lamellar structure top) is transformed into a cubic phase bottom). Reproduced with permission from ref. [128]...

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