Correlation between bioactivity and structural properties of titanium dioxide coatings grown by atomic layer deposition

Abstract TiO 2 coatings were grown on Ti and Si by Atomic Layer Deposition (ALD) from titanium ethoxide and water at 300 °C in a wide range of the reaction cycles number N  = 100–2000. TiO 2 coatings were found to be amorphous at low value of N N  ≥ 300 revealed anatase polycrystalline structure. The TiO 2 coatings bioactivity was evaluated by hydroxyapatite forming ability by the technique of soaking in Simulated Body Fluid (SBF). Correlation between bioactivity and structural properties of TiO 2 was determined. X-ray diffraction and scanning electron microscopy with electron probe microanalysis showed that amorphous TiO 2 coating did not induce the hydroxyapatite growth whereas anatase resulted in the hydroxyapatite forming on the samples surfaces which confirmed TiO 2 anatase bioactivity.