XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
211
T1: P–78
Characterization of sp
3
content of carbon films deposited by high power
gas injection magnetron sputtering method by UV and VIS Raman
spectroscopy
Krzysztof Zdunek
1
, Rafał Chodun
1
, Bartosz Wicher
1
,
Katarzyna Nowakowska-Langier
2
, Sebastian Okrasa
1
1
Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-
507 Warsaw, Poland, e-mail: rafal.chodun@inmat.pw.edu.pl
2
National Centre for Nuclear Research (NCBJ), A. Soltana 7, 05-400 Otwock, Poland
This work presents vibrational spectra of carbon films deposited by modified version of
magnetron sputtering method. Our purpose was to make favorable conditions for carbon
amorphization to achieve a deposit containing significant fraction of sp
3
bonds. According to the
Ferrari diagram of 3 – stage carbon amorphization [1] the sp3 bonding is expected when in –
plane correlation length Ls is below 2 nm [2]. We used high power method for plasma excitation
carried out by magnetron system with inversely polarized electrodes: sputtered cathode at
ground potential and positively biased, in – space separated anode [3]. This arrangement
allowed us to use voltages ranging from 1 to 2 kV and power supply system with 25 µF
capacitor battery equipped. Additionally, we used the pulse manner of working gas distribution
to initiate the discharges. This method of initiation the plasma impulses we used introducing the
novel method of magnetron sputtering – GIMS method (Gas Injection Magnetron Sputtering)
[4]. Our previous studies showed that created conditions favor the energy exchange between
energetic plasma species and surface of the substrate [5].
Raman scattering of deposited films was examined by Jasco NRS 5100 spectrometer using
532 and 266 nm excitation wavelength. Registered spectra were fitted with components
indicating T, D and G phonon modes. Evaluation of sp3 content was performed basing on ID/IG
ratio, G peak dispersion, G peak position and G peak FWHM. Fig.1 presents exemplary spectra
of carbon film containing 65% of sp
3
. We observed the changes of sp
3
content in a function of
plasma impulse energy and impulse frequency. The article discuss the evolution of these factors
in a function of plasma impulse energy and frequency of plasma pulses. We believe that ranging
phase state is the result of material degradation under bombardment of energetic plasma species.
Fig. 1. Raman spectra of carbon films registered under various wavelength excitation.
Keywords: DLC films, Raman spectroscopy, magnetron sputtering, gas injection magnetron sputtering
Acknowledgment
This work was supported by the National Science Centre.
References
[1] A.C. Ferrari, et al., Phys. Rev. B 62 (2000) 11089.
[2] F. Tuinstra, J.L. Koenig, J. Chem. Phys. 53 (1970) 1126.
[3] R. Chodun, et al., Nukleonika, 61 (2016) 191.
[4] K. Zdunek, et al., Materials Science-Poland 32 (2014) 171.
[5] L. Skowronski, et al. Surf. Coat. Technol. 282 (2015) 16.
XIV
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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
212
T1: P–79
Hydroxyapatite-chitosan based bioactive hybrid biomaterials
with improved mechanical strength
Aneta Zima
1
, Joanna Czechowska
1
, Dominika Siek
1
, and Anna Ślósarczyk
1
1
Department of Ceramics and Refractories, AGH University of Science and Technology, 30
Mickiewicza AV., 30-059 Krakow, Poland, e-mail: azima@agh.edu.pl
The next generation of synthetic bone implants constitutes the combination of bioresorbable
polymers with inorganic bioactive components. This allows accurately reproducing the bone
microstructure and activating the mechanisms of bone tissue regeneration. Recently the attention
has been drawn to hydroxyapatite (HA)-chitosan (CTS) composite biomaterials, which show
promise in mimicking both, the organic and inorganic part of natural bone. Hydroxyapatite due
to its close chemical and crystal resemblance to the mineral phase of bone exhibits excellent
biocompatibility and osteoconductivity. Chitosan (CTS) is a biopolymer which belongs to the
group of polysaccharides. It is obtained by deacetylation of chitin. The biological properties of
chitosan make it an ideal component of implant materials, including calcium phosphate-chitosan
composites. Previous studies regarding applications of composites based on hydroxyapatite and
chitosan in the reconstruction and regeneration of bone were mainly focused on the fabrication
of scaffolds. Simple mixing method is one of the most popular approach to obtain chitosan-HA
composites. In this work a novel inorganic-organic (I/O) HA/CTS materials in the form of
granules were prepared through a simple solution-based chemical method. During the synthesis
of above hybrids the electrostatic complexes between positively charged, protonated amine
groups of chitosan and the negative phosphates species (HPO
4
2–
and H
2
PO
4
–
) were formed. Our
biocomposites belong to the class I of hybrids, what was confirmed by FTIR studies. XRD
analysis revealed that obtained materials consisted of hydroxyapatite as the only one crystalline
phase. Homogeneous dispersion of the components in HA/CTS composites was confirmed. The
application of 17 wt. % (H2C) and 23 wt.% (H3C) of chitosan resulted in approximately 12-fold
and 16-fold increase in the compressive strength of HA/CTS as compared to the non-modified
HA material. During incubation of the studied materials in SBF pH of solution remained close to
the physiological one. Formation of apatite layer on their surfaces indicated on bioactive
character of the developed hybrids.
Fig. 1. SEM microphotographs of H2C and H3C hybrid granules.
Keywords: hybrid granules, hydroxyapatite, chitosan, bone substitutes.
Acknowledgment
This work was supported by the Faculty of Materials Science and Ceramics, AGH University of Science
and Technology - Project No. 11.11.160.617 (2017).
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