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 d egrees 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 w ater on the sample surface, allowing its maturation. At 40 and 60 degrees C , the upper surface, rich in adsorbed water, crystallizes into triclinic OC P, a compound with structural water. The other deeper part leads to apatiti c OCP, Whatever the temperature, both types of crystal decompose with time, in various stages, to finally lead to a mixture of hydroxyapatite and mone tite. (C) 1999 Academic Press.