Crystallization, fluoridation and some properties of apatite thin films prepared through rf-sputtering from CaO-P2O5 glasses.
Using calcium phosphate glass targets with the CaO/P2O5 molar ratios of 1.50-0.50, much lower than the stoichiometric value of 3.3 for hydroxyapatite, thin films of stoichiometric hydroxy-, nonstoichiometric oxyhydroxy- and Ca-deficient oxyhydroxy-apatites were prepared on alumina ceramic substrates by rf-sputtering followed by post-annealing. Based on the present results, a phase diagram for CaO-P2O5 at low temperatures in the ambience of air was depicted for thin films. The ambient H2O vapor had an influence on the phase diagram: Tricalcium phosphate was changed to apatite in the presence of H2O vapor. Dense fluorohydroxyapatite thin films were prepared by fluoridation of those apatite thin films at a low temperature such as 200 degrees C. In the present report, some functional properties of thin films thus prepared were also shown.
Division of Inorganic Materials, Institute for Medical and Dental Engineering, Tokyo Medical and Dental University, Japan. yama-k@imde.tmd.ac.jp
K
K
Yamashita
M
M
Matsuda
T
T
Arashi
T
T
Umegaki
D000537:Aluminum Oxide; D001031:Apatites / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D002516:Ceramics; D003460:Crystallization; D004553:Electric Conductivity; D005459:Fluorides / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D017553:Phosphorus Compounds / Q000737:chemistry; D013499:Surface Properties
D001031:Apatites; D017610:Calcium Compounds; D002130:Calcium Phosphates; D010087:Oxides; D017553:Phosphorus Compounds; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C012500:phosphorus pentoxide; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C016538:lime; C485829:calcium phosphate, dibasic, anhydrous; D000537:Aluminum Oxide; D005459:Fluorides