The Synthesis of Diamond Application to Phase Changes

Akin to the alchemist s dream of converting lead into gold has been the desire to convert graphite to diamond from the simple chemical process. 

It is well known that graphite is the stable form of carbon at ambient conditions, and studies have been undertaken to find pressure and temperature conditions where diamond becomes stable, and as a consequence, graphite would convert spontaneously to diamond. The process is fraught with difficulty, and for many years the conversion was not successful. The 

In order to bring the graphite-diamond reaction into a region where AG° is negative, it is necessary to apply pressure. The pressure required depends on the temperature — the higher the temperature, the greater must be the pressure. 

Equilibrium is established when the free energy difference between the two allotropes is zero, that is, 

The manner in which AG varies with pressure at a given temperature is given by 

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