2006 Volume 70 Issue 4 Pages 330-336
Amorphous and crystallized calcium phosphate (Ca-P) coatings on Ti substrate have been investigated by X-ray photoelectron spectroscopy (XPS). The Ca-P coating on Ti substrate was performed by radio frequency magnetron sputtering of a sintered hydroxyapatite (HAp) target. As-sputtered Ca-P coating having 1.81 of Ca/P ratio was amorphous. Annealing the as-sputtered amorphous coating at 600°C resulted in crystallized coating into HAp and tetracalcium phosphate (TTCP). The XPS profile of amorphous coating is almost the same as that of annealed coating. The XPS profile of oxygen in the amorphous coating shows that oxygen atom combines with both phosphorus and calcium atoms, indicating the amorphous coating contains fundamental chemical bonds of both HAp and TTCP.