Pulsed laser deposition of hydroxyapatite thin films on Ti-5A1-2.5Fe substrates with and without buffer layers

We present a method for processing hydroxyapatite (HA) thin films on Ti-5Al -2.5Fe substrates. The films were grown by pulsed laser deposition (PLD) in vacuum at room temperature, using a KrFdouble dagger excimer laser. The am orphous as-deposited HA films were recrystallized in ambient air by a therm al treatment at 550 degreesC. The best results have been obtained when inse rting a buffer layer of ceramic materials (TiN, ZrO2 or Al2O3) The films we re characterized by complementary techniques: grazing incidence X-ray diffr action (GIXRD), scanning electron microscopy (SEM), cross-section transmiss ion 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 c haracteristics as compared with that without buffer interlayer. (C) 2000 Pu blished by Elsevier Science B.V.