Basic growth mechanism with gaseous diffusion

Basic growth mechanism with gaseous diffusion 

To describe a chemical model, it is necessary to specify the reacting species and the intermediate forms. The model applies to a family of reactions and must be transposed, with other species, for the other families. We can express this model in the case of the decomposition of an MCO3 metal carbonate into carbon dioxide and MO oxide. It is thus about the decomposition without redox reaction of the anion and the cation but with the formation of the gas molecule by the decomposition of the anion. 

We asstrme that the mechanism involves fotrr elemerrlary steps. Three of the steps are localized at the carbonates/oxide interface (irrtemal irrterface). 

The first step is the creation of point defects on the sirrface of carbonate by decomposition of the carbonate ions and motion of carbon dioxide molecules to adsorbed places onto an s site on the surface of carbonate. This reaction is expressed by means of strrface structure elemerrts  

The second step consists of desorption of carbon dioxide according to 

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Basic growth mechanism with gaseous diffusion... 

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