Behavior in Wet Atmosphere of an Amorphous Calcium Phosphate with an Atomic Ca/P Ratio of 1.33

This study deals with the behavior, in a wet atmosphere at 40, 60, and 80°C, of an amorphous calcium phosphate with an atomic Ca/P ratio of 1.33. The wet atmosphere treatment leads to the formation of a thin film of water on the sample surface, allowing its maturation. At 40 and 60°C, the upper surface, rich in adsorbed water, crystallizes into triclinic OCP, a compound with structural water. The other deeper part leads to apatitic OCP. Whatever the temperature, both types of crystal decompose with time, in various stages, to finally lead to a mixture of hydroxyapatite and monetite.