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Influence of the Chemical Composition on the Phase Constitution and the Elastic Properties of RF‐Sputtered Hydroxyapatite Coatings
Author(s) -
Snyders Rony,
Bousser Etienne,
Music Denis,
Jensen Jens,
Hocquet Stéphane,
Schneider Jochen M.
Publication year - 2008
Publication title -
plasma processes and polymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 74
eISSN - 1612-8869
pISSN - 1612-8850
DOI - 10.1002/ppap.200700112
Subject(s) - elastic modulus , materials science , x ray photoelectron spectroscopy , chemical composition , diffraction , analytical chemistry (journal) , sputtering , bulk modulus , stoichiometry , phase (matter) , mineralogy , composite material , thin film , chemistry , nuclear magnetic resonance , nanotechnology , optics , physics , organic chemistry , chromatography
We have studied the influence of chemical composition on the constitution and elastic properties of dense radio‐frequency (RF)‐sputtered hydroxyapatite (HA) coatings. The chemical composition was modified by varying the RF sputtering power density ( P D ). As the P D was increased by 240%, the Ca/P ratio measured by X‐ray photoelectron spectroscopy increased from ≈1.51 to ≈1.82. X‐ray diffraction indicates phase pure hexagonal HA except for the sample prepared at the highest P D where CaO and Ca 3 (PO 4 ) 2 also form. Deviations from the stoichiometric Ca/P ratio result in reduction of the elastic modulus. For Ca/P = 1.51 ± 0.02, the elastic modulus decreases by ≈15%. This may be due to incorporation of Ca vacancies in the lattice, while for Ca/P = 1.82 ± 0.02, the average elastic modulus decreases by ≈10% due to formation of additional phases.