Poly-crystallization of hydroxyapatite coatings deposited by PLD method at room temperature

Hydroxyapatite (HAp) is a biological and bioactive material, which has promise as a coating material for orthopedic and dental implants. Some HAp coating methods have been investigated and the pulsed laser deposition (PLD) method is one of the most candidate. Previous PLD researchers deposited the HAp coatings on heated Ti and Ti-alloy substrates in order to crystallize the coatings. However, the deposition condition, high substrate temperature and water atmosphere, should promote the oxidation of the substrate surface prior to the growth of the HAp layer, which degrades the adhesion of the coating to the substrate. Therefore, HAp coatings should be deposited at lower temperature to avoid extensive oxidation of the substrates.