TY - JOUR
T1 - The Influence of argon gas pressure on co-sputtered calcium phosphate thin films
AU - Boyd, A
AU - Duffy, H
AU - McCann, R
AU - Cairns, ML
AU - Meenan, BJ
PY - 2007/5
Y1 - 2007/5
N2 - A series of Ca-P coatings have been co-deposited by RF magnetron sputtering from hydroxyapatite targets at a range of different argon gas pressures (1-5 Pa) at a low discharge power level. The resultant surfaces were analysed both as-deposited and after annealing at 500 degrees C using fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and stylus profilometry. The deposition rate increased with increasing argon gas pressure up to 2 Pa, but decreased significantly as the pressure increased up to 5 Pa. The Ca/P ratios of the as-deposited coatings were lower than expected, and decreased significantly at the higher argon gas pressures. The corresponding FTIR and XRD data showed that the as-deposited surfaces were poorly hydroxylated and were mostly amorphous in nature. By comparison, the annealed surfaces had Ca/P ratios of between 3.38 +/- 0.11 (1 Pa) and 1.82 +/- 0.06 (5 Pa). The FTIR and XRD data for the annealed samples were indicative of HA, however, as the gas pressure increased above 3 Pa, these surfaces were most likely transformed into dehydroxylated HA. This study has shown the utility of varying the argon gas pressure whilst co-sputtering HA in order to modify the resultant surface conditions. (c) 2007 Elsevier B.V. All rights reserved.
AB - A series of Ca-P coatings have been co-deposited by RF magnetron sputtering from hydroxyapatite targets at a range of different argon gas pressures (1-5 Pa) at a low discharge power level. The resultant surfaces were analysed both as-deposited and after annealing at 500 degrees C using fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and stylus profilometry. The deposition rate increased with increasing argon gas pressure up to 2 Pa, but decreased significantly as the pressure increased up to 5 Pa. The Ca/P ratios of the as-deposited coatings were lower than expected, and decreased significantly at the higher argon gas pressures. The corresponding FTIR and XRD data showed that the as-deposited surfaces were poorly hydroxylated and were mostly amorphous in nature. By comparison, the annealed surfaces had Ca/P ratios of between 3.38 +/- 0.11 (1 Pa) and 1.82 +/- 0.06 (5 Pa). The FTIR and XRD data for the annealed samples were indicative of HA, however, as the gas pressure increased above 3 Pa, these surfaces were most likely transformed into dehydroxylated HA. This study has shown the utility of varying the argon gas pressure whilst co-sputtering HA in order to modify the resultant surface conditions. (c) 2007 Elsevier B.V. All rights reserved.
U2 - 10.1016/j.nimb.2007.02.072
DO - 10.1016/j.nimb.2007.02.072
M3 - Article
VL - 258
SP - 421
EP - 428
JO - Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
IS - 2
ER -