X-ray and neutron diffraction studies of crystallinity in hydroxyapatite coatings

To standardize industrial implant production and make comparisons between d ifferent experimental results, we have to be able to quantify the crystalli nity of hydroxyapatite. Methods of measuring crystallinity ratio were devel oped fur various HA samples before and after plasma spraying. The first ser ies of methods uses X-ray diffraction. The advantage of these methods is th at X-ray diffraction equipment is used widely in science and industry. In t he second series, a neutron diffraction method is developed and the results recorded are similar to those obtained by the modified X-ray diffraction m ethods. The advantage of neutron diffraction is the ability to obtain measu rements deep inside a component. It is a nondestructive method, owing to th e very low absorption of neutrons in most materials. (C) 2000 John Wiley & Sons, Inc.