Physicochemical investigation of pulsed laser deposited carbonated hydroxyapatite films on titanium.
Carbonated hydroxyapatite (CHA)-coated titanium can find wide applications as bone substitute implant in bone and dental surgery and orthopedics, promoting osseointegration with a host bone and ensuring biocompatibility and bioactivity. In this work, carbonated hydroxyapatite films were prepared on titanium substrates by pulsed laser deposition at different substrate temperatures ranging from 30 to 750 degrees C. The properties of films were investigated by scanning electron microscopy, atomic force microscopy, energy-dispersive X-ray diffraction, and Fourier transform infrared spectroscopy. Vickers microhardness measurements of the composite film-substrate systems were performed, and the intrinsic hardness of films was separated from the composite hardness using a "law-of-mixtures" approach and taking into account the indentation size effect. The prepared CHA films are nearly stoichiometric with a Ca/P atomic ratio of 2.0-2.2. The films deposited in the 30-500 degrees C temperature range are about 9 microm thick, amorphous, having an average roughness of 60 nm. At higher temperature, 700-750 degrees C, the films are about 4 microm thick, show a finer surface morphology and an average roughness of 20 nm. At 750 degrees C the films are amorphous, whereas at 700 degrees C they are crystalline and textured along the (202) and (212) directions. The intrinsic hardness of the films increased with an increase in substrate temperature, being as low as 5 GPa at 30 degrees C and reaching a high value of 28 GPa at 700 degrees C. The rich information gained by the joint use of the mentioned techniques allowed a comprehensive characterization of this system.
Rau
Julietta V
JV
Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere 100, 00133 Rome, Italy. giulietta.rau@ism.cnr.it
Generosi
Amanda
A
Laureti
Sara
S
Komlev
Vladimir S
VS
Ferro
Daniela
D
Cesaro
Stella Nunziante
SN
Paci
Barbara
B
Albertini
Valerio Rossi
VR
Agostinelli
Elisabetta
E
Barinov
Sergey M
SM
D018786:Bone Substitutes / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002627:Chemistry, Physical / Q000379:methods; D006882:Hydroxyapatites / Q000737:chemistry*; D007834:Lasers; D008422:Materials Testing; D018625:Microscopy, Atomic Force / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods; D010710:Phosphates / Q000737:chemistry; D011312:Pressure; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013696:Temperature; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction
D018786:Bone Substitutes; D006882:Hydroxyapatites; D010710:Phosphates; D002244:Carbon; D014025:Titanium; D002118:Calcium