Mixed calcium-cobalt orthophosphates, of the general formula Ca3-xCOx(PO4)2 with 0≤x≤1.1, were prepared by coprecipitation. Reactions which occur during heating from room temperature to 850°C, of either
tricalcium phosphate or mixed Ca−Co phosphates, were monitored by thermogravimetry and differential thermal analysis. The
dried precipitates and the final products were characterised by X-ray diffraction and infrared spectroscopy.