Growth of Crystalline Hydroxyapatite Thin Films at Room Temperature by Tuning the Energy of the RF-Magnetron Sputtering Plasma

López, Elvis O.; Mello, Alexandre; Sendão, Henrique; Costa, Lucas Teixeira; Rossi, André L.; Ospina, Rogelio; Borghi, Fabricio Frizera; Filho, José G. Silva; Rossi, Alexandre M.

doi:10.1021/am4020007

Cited by 68 publications

(82 citation statements)

References 69 publications

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“…All peaks were indexed to a pure HAp according to the ICCD-PDF#00-009-0432 database. Some strongly preferred orientations for the (100) and (002) planes are usually found for HAp sputtered thin films [51]. For the thicker film of this work, the GIXRD pattern also shows higher relative intensities (I hkl /I 211 ) as compared to the ones found in the ICCD database.…”

Section: Preparation and Characterization Of The Hap Thin Filmssupporting

confidence: 62%

Energy deposition of H and He ion beams in hydroxyapatite films: A study with implications for ion-beam cancer therapy

et al. 2014

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Ion-beam cancer therapy is a promising technique to treat deep-seated tumors; however, for an accurate treatment planning, the energy deposition by the ions must be well known both in soft and hard human tissues. Although the energy loss of ions in water and other organic and biological materials is fairly well known, scarce information is available for the hard tissues (i.e., bone), for which the current stopping power information relies on the application of simple additivity rules to atomic data. Especially, more knowledge is needed for the main constituent of human bone, calcium hydroxyapatite (HAp), which constitutes 58% of its mass composition. In this work the energy loss of H and He ion beams in HAp films has been obtained experimentally. The experiments have been performed using the Rutherford backscattering technique in an energy range of 450-2000 keV for H and 400-5000 keV for He ions. These measurements are used as a benchmark for theoretical calculations (stopping power and mean excitation energy) based on the dielectric formalism together with the MELF-GOS (Mermin energy loss function-generalized oscillator strength) method to describe the electronic excitation spectrum of HAp. The stopping power calculations are in good agreement with the experiments. Even though these experimental data are obtained for low projectile energies compared with the ones used in hadron therapy, they validate the mean excitation energy obtained theoretically, which is the fundamental quantity to accurately assess energy deposition and depth-dose curves of ion beams at clinically relevant high energies. The effect of the mean excitation energy choice on the depth-dose profile is discussed on the basis of detailed simulations. Finally, implications of the present work on the energy loss of charged particles in human cortical bone are remarked.

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Section: Preparation and Characterization Of The Hap Thin Filmssupporting

confidence: 62%

Energy deposition of H and He ion beams in hydroxyapatite films: A study with implications for ion-beam cancer therapy

et al. 2014

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“…The RAMS system used in this work had the same setup as that described elsewhere [33,35]. It was composed of two magnetrons positioned face-to-face operating at 13.56 MHz.…”

Section: The Rams System and Plasma Characterisationmentioning

confidence: 99%

“…The floating potential of the substrate holder was used to improve thin-film crystallinity [33,35]. Plasma energies at different distances from the substrate position (Z = 29 mm) were evaluated by a Langmuir probe.…”

Section: The Rams System and Plasma Characterisationmentioning

confidence: 99%

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Crystalline nano-coatings of fluorine-substituted hydroxyapatite produced by magnetron sputtering with high plasma confinement

López

Rossi

Archanjo

et al. 2015

Surface and Coatings Technology

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a b s t r a c tA radio-frequency magnetron sputtering technique operating in right-angle geometry (RAMS) with high plasma confinement was revised to produce thin films (15-570 nm) of fluorine-substituted hydroxyapatite, FHA, adapted to be used as nano-coatings for biomedical implants. An electron temperature of T eff ≈ 9.0 eV and a plasma electron density of 1.2 × 10 15 m −3 assured the nucleation of an amorphous fluorine-substituted hydroxyapatite phase on Si and Ti surfaces. With the aid of a Langmuir probe, the RAMS plasma energy was tuned to control the coating stoichiometry and the ratio between the crystalline and amorphous phases. The energy delivered over time from the bombardment of ions and electrons transformed the amorphous calcium phosphate phase into crystalline fluorine-substituted hydroxyapatite. The crystalline films were obtained at room temperature. The partial substitution of OH − for F − in the HA structure was confirmed by X-ray diffraction using synchrotron radiation in grazing-incidence mode, X-ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. High-resolution transmission electron microscopy carried out on crosssection film samples prepared by a focused ion beam (FIB) technique revealed that the film ultrastructure was composed of columnar crystals oriented perpendicularly to the substrate surface. The crystals were connected to the substrate surface by ordered nanolayers, indicating the existence of a continuous binding between the two materials. This work demonstrates that the RAMS technique is able to produce FHA nano-coatings with controlled chemical compositions and structures on metallic implants for clinical applications.

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“…3 (b) reveals the formation of valleys on the surface of the deposited films. These valleys increase the average surface roughness of the coating to nearly 4.98 nm which is higher than the 2.6 nm roughness reported by Lopez et al [34]. It is already well established that human osteoblasts attach more readily to surfaces with a roughness less than 500 nm than to surfaces with a roughness greater than 2000 nm [35].…”

Section: Surface Morphologymentioning

confidence: 71%

Surface morphology andin vitrobioactivity of biocompatible hydroxyapatite coatings on medical grade S31254 steel by RF magnetron sputtering deposition

Das

Shukla

2017

Transactions of the IMF

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Hydroxyapatite (HA) is popularly used as a bio-compatible coating material for metallic implants, in view of its improved bone fixation property, leading to an increased life of the implant. However, the deposition of HA on medical grade UNS S31254 stainless steel (SS254) for orthopaedic implant applications by the radio-frequency magnetron sputtering technique is unreported in the literature so far. The surface morphology of deposited HA coatings was characterized using Scanning Electron Microscopy and Atomic Force Microscopy, while their phase composition was determined using X-ray Diffraction. The thickness and adhesive strength of the HA coatings were determined using an Ellipsometer and a Tensometer, respectively. Finally, the antibacterial efficacy and bioactivity of the deposited coatings were confirmed using Fluorescence Activated Cell Sorting and Immersion test in Simulated Body Fluid environment. The obtained results showed that the HA coatings grown on SS254 using magnetron sputtering possess desirable surface properties as well as adhesion and biocompatibility properties, ideally suited for potential applications in orthopaedic implants.

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Growth of Crystalline Hydroxyapatite Thin Films at Room Temperature by Tuning the Energy of the RF-Magnetron Sputtering Plasma

Cited by 68 publications

References 69 publications

Energy deposition of H and He ion beams in hydroxyapatite films: A study with implications for ion-beam cancer therapy

Energy deposition of H and He ion beams in hydroxyapatite films: A study with implications for ion-beam cancer therapy

Crystalline nano-coatings of fluorine-substituted hydroxyapatite produced by magnetron sputtering with high plasma confinement

Surface morphology andin vitrobioactivity of biocompatible hydroxyapatite coatings on medical grade S31254 steel by RF magnetron sputtering deposition

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