Mott-Gurney model

The understanding of the basic mechanism of photolysis of silver halide is incomplete yet vital for the planning and interpretation of experiments. This fact is illustrated by the ramifications inherent in the contemporary discussions of the latent image in silver halide. There are the conventional Gurney-Mott mechanism (1) and the thermodynamic model ((5,9). We have described the Gurney-Mott model. The thermodynamic view envisages nucleation of a supersaturated concentration of silver atoms in silver halide as induced by light. Obviously the effect of external variables is quite different in the two mechanisms. 

In the microcrystalline models the amorphous solid is considered as being composed of an assembly of very small, highly ordered regions separated from each other by regions of much lower atomic order. (Valenkov and Porai-Koshits, 1973 Mott and Gurney, 1938). These models come quite close to cluster models in which... 

In recent years, the pre-transition-state idea of Gurney has been taken up again by Dogonadze, Levich, and co-workers, H who have used a model for the classical subsystem that is based on Landau s work, " and which was applied by Mott and Gurney and Pekar to crystals, and in modified form by Libby and Weiss to electrolytes. This idea makes use of continuum physics to obtain a description of the potential energy of an ion in solution, in a highly simplified model which is purely electrostatic. 

Further evidence for electronic conduction was obtained by studying the dependence of current on apphed voltage. For ionic conduction, a model based on the work of Mott and Gurney shows that ionic current is related to applied voltage by the following expression [18] ... 

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