Pulsed laser deposition of hydroxyapatite thin ®lms on Ti-5Al-2.5Fe substrates with and without buffer layers

We present a method for processing hydroxyapatite (HA) thin ®lms on Ti-5Al-2.5Fe substrates. The ®lms were grown by pulsed laser deposition (PLD) in vacuum at room temperature, using a KrF excimer laser. The amorphous as-deposited HA ®lms were recrystallized in ambient air by a thermal treatment at 5508C. The best results have been obtained when inserting a buffer layer of ceramic materials (TiN, ZrO2 or Al2O3). The ®lms were characterized by complementary techniques: grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy (SEM), cross-section transmission electron microscopy (XTEM), SAED, energy dispersive X-ray spectroscopy (EDS) and nanoindentation. The samples with buffer interlayer preserve the stoichiometry are completely recrystallized and present better mechanical characteristics as compared with that without buffer interlayer. # 2000 Published by Elsevier Science B.V.