Title
The role of lower hybrid resonance and helicon waves excitations in a magnetized plasma for coating production of complex crystalline structures as hydroxyapatite
Date Issued
01 December 2017
Access level
metadata only access
Resource Type
journal article
Author(s)
Borges F.O.
Rossi A.M.
Galvão R.M.O.
Mello A.
Brazilian Center for Research in Physics (CBPF)
Publisher(s)
Elsevier Ltd
Abstract
The non-equilibrium electro-thermodynamic properties of magnetized plasma produced by a modified radio-frequency magnetron sputtering system were investigated in detail. The plasma was analyzed using Hall, Langmuir, and Faraday probes and optical emission spectroscopy, and numerical simulations were conducted to determine the electric and magnetic field profiles. It is found that the occurrence of lower hybrid resonance and excitation of helicon waves are satisfied locally along the plasma profile (Z). This unusual effect in magnetron sputtering systems plays an important role in the increase of the electrons and ions temperature improving the quality of the films produced. Films of complex structure as hydroxyapatite that have biomedical applications were produced along the Z to confirm our plasma results. The films were characterized by performing grazing incidence X-ray diffraction using synchrotron radiation, X-ray photoelectron spectroscopy and atomic force microscopy. The microstructure analysis of hydroxyapatite films produced at different Z revealed that films with high crystallinities and with ideal stoichiometries (Ca/P = 1.67 ± 0.05) were produced within a magnetic cusp region (26 mm < Z < 32 mm). Based upon the results from plasma diagnostics and films characterization, we proposed a model of plasma of this system. The delivered energy by ions bombardment for films formation was determined and reached values around 8 eVs−1Å−2 and plasma temperature of T ≈ 10 eV inside the magnetic cusp region. Finally, this work opens the possibility to produce coatings of other complex compounds by the fine-tuning of resonant waves and their high delivered energies in vacuum magnetized plasmas.
Start page
233
End page
245
Volume
146
Language
English
OCDE Knowledge area
Ingeniería eléctrica, Ingeniería electrónica Biofísica Biotecnología relacionada con la salud
Scopus EID
2-s2.0-85030998832
Source
Vacuum
ISSN of the container
0042207X
Sponsor(s)
The authors wish to thank the Synchrotron Light Brazilian National Laboratory (LNLS) in Campinas-Brazil for the GIXRD measurements, the X-Ray Diffraction Multiuser Laboratory of the CBPF for the XRR measurements, the Biomaterials Laboratory (LABIOMAT) of the CBPF for synthesizing the hydroxyapatite powder, the Multiuser Laboratory of Surfaces and Nanostructures of the CBPF, the Brazilian government agency CAPES for the scholarship grant awarded.
Sources of information: Directorio de Producción Científica Scopus