Effect of processing parameters on the properties of hydroxylapatite films grown by pulsed laser deposition

Abstract Thin films of hydroxylapatite (HA) (Ca10(PO4)6(OH)2) were created on Ti substrates by KrF laser ablation. The layers were deposited in vacuum, in pure H2O vapours (pressure, 2 × 10−3 to 2 × 10−1 mbar) and in an Ar-H2O vapour mixture. The influence of the laser energy density ET (3 J cm−2, 13 J cm−2) and substrate temperature Ts (500–760 °C) on the film parameters was studied. Two different processes were used for HA target preparation. Films and targets were characterized by Rutherford backscattering (RBS) analysis, particle induced X-ray emission (PIXE), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Knoop microhardness and scratch tests. For lower Ts and higher ET, the Ca/P ratio in the films was similar to that in the HA target. Crystalline HA peaks were found preferentially in the films deposited in the presence of Ar-H2O vapours. Time of flight (TOF) spectra of the plasma plume from the HA target were also analysed.