Deposition of Bio-Integration Ceramic Hydroxyapatite by Pulsed-Pressure MOCVD Using a Single Liquid Precursor Solution

Pulsed‐pressure (PP) metal‐organic(MO)CVD is used to deposit layers of calcium phosphate onto flat bio‐medical grade titanium (Ti6Al4V) substrates. Inexpensive calcium lactate and trimethyl phosphate (TMP), combined in a methanol solution, forms the precursor. A range of precursor mixtures is studied by thermogravimetric analysis (TGA) to assess reaction pathways. The surface topography, morphology, composition, and crystallinity are studied over a range of deposition temperatures and precursor concentrations. The resulting films are analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X‐ray diffraction (XRD), Raman spectroscopy (RS), and micro‐indentation. The films are continuous and the size of surface structures increases at higher temperatures and precursor concentration. The films consist of amorphous calcium phosphate in elemental Ca/P ratios similar to the standard bio‐ceramic, hydroxyapatite (1.66). Hydroxyapatite films have been prepared by pulsed‐pressure MOCVD by single source liquid precursor using calcium lactate and tri‐methyl phosphate. The precursor mixture, deposition temperature and precursor concentration to produce calcium phosphate with the stoichiometry of hydroxyapatite were investigated. Fully amorphous hydroxyapatite was produced with very interesting topology with spherical morphology. The deposition formed a solid, adherent, conformal layer on the biomedical grade titanium alloy substrates with chaotic spherical and nebulous structures growing normal to the substrate. The number and profile of the spherical structures increased with temperature and precursor concentration.