Hydroxyapatite coatings grown by pulsed laser deposition with a beam of 355 nm wavelength

摘要

Calcium phosphate coatings, obtained at differentdeposition rates by pulsed laser deposition with a Nd:YAG laserbeam of 355 nm wavelength, were studied. The deposition ratewas changed from 0.043 to 1.16 A/shot by modification of onlythe ablated area, maintaining the local fluence constant to performthe ablation process in similar local conditions. Characterizationof the coatings was performed by scanning electron microscopy, x-ray diffractometry, and infrared, micro-Raman, and x-rayphotoelectron spectroscopy. The coatings showed a compactsurface morphology formed by glassy grains with some droplets onthem. Only hydroxyapatite (HA) and alpha-tricalcium phosphate(#alpha#-TCP) peaks were found in the x-ray diffractograms. Therelative content of #alpha#-TCP diminished with decreasingdeposition rates, and only HA peaks were found for the lowest rate.The origin of #alpha#-TCP is discussed.