XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
196
T1: P–63
Spectroscopic structural studies of yttria co-doped with Nd
3+
and La
3+
synthesized by means of EDTA gel processing
Michał Bobruk
1
, Anna Adamczyk
1
, Andrzej Kruk
2
, and Tomasz Brylewski
1
1
Material Science and Ceramics Department, AGH University of Science and Technology, Al.
Mickiewicza 30, 30-059 Cracow, Poland, e-mail: aadamcz@agh.edu.pl
2
University of Information Technology and Management, ul. Sucharskiego 2, 35-225 Rzeszów,
Poland
New materials and manufacturing methods are developed to meet the current scientific and
technological needs. Such materials include polycrystalline yttrium oxide – Y
2
O
3
. It is a very
promising compound owing to its high melting point of ca. 2450°C, good chemical stability,
relatively good mechanical properties, and a low thermal expansion coefficient. Its
advantageous properties enable various applications, which include materials for sight glasses
operating in aggressive environments and at high temperatures [1, 2].
In this work, spectroscopic studies of the microstructure of yttria co-doped with Nd
3+
and
La
3+
were conducted to establish the influence of the concentration of the components
introduced into the crystal lattice of Y
2
O
3
. Theoretically, for Y
2
O
3
, it is possible to observe 16 IR
spectroscopic active vibrations, 22 Raman spectroscopic active ones, and 22 inactive vibrations
in the above-mentioned spectroscopy types. In the measured FTIR spectra of pure yttria and
yttria co-doped with Nd
3+
and La
3+
, there are three main regions where bands specific to
particular vibrations are observed. At about 3500 cm
–1
, bands typical of OH group vibrations
occur, while in the range of 1700–900 cm
–1
, bands attributed to the vibrations of CO
2
, H
2
O and
CO
3
2–
groups are observed. The third region covers the range of 600–400 cm
–1
, i.e. the region of
pseudolattice vibrations. Main bands specific to the vibrations of yttria's crystal lattice are
located at 565, 464, 417 cm
–1
(more intensive bands) and at 515, 490, and 445 cm
–1
(weaker
ones). When Nd
3+
and La
3+
ions were incorporated into the yttria structure, bands in the last
mentioned range shifted to lower wavelengths. The same effect was also observed in the Raman
spectra, where only bands specific to Y
2
O
3
were observed (seven bands of 5Fg, Eg and Ag
symmetry).
The presence of bands specific to the Y
2
O
3
structure in both FTIR and Raman effect spectra
confirms the crystallization of the Y
2
O
3
type structure in the case of all synthesized samples and
the complete incorporation of the added Nd
3+
and La
3+
ions into this structure.
Keywords: Y
2
O
3
; microstructure; wet chemistry method; FTIR spectroscopy; Raman spectroscopy
Acknowledgment
The financial support of the AGH University of Science and Technology, Grant No. 11.11.160.767.
References
[1] H. Eilers, J. Eur. Ceram. Soc. 27 (2007) 4711.
[2] A. Wajler, H. Węglarz, H. Tomaszewski, M. Możdżonek, A. Sidorowicz, Z. Librant, Ceramics
Materials 64 (2012) 108.
XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
197
T1: P–64
The influence of sol concentration on the properties of layers deposited
on the metal substrate
Magdalena Rokita
1
1
AGH University of Science and Technology, Department of Material Science and Ceramics, 30-059
Kraków, al. Mickiewicza 30, Poland, e-mail: rokita@agh.edu.pl
Covering the metal material with the sol layer enables modification of the properties of the
substrate. Rendering such bioproperties to the metallic base as biocompatibility and bioactivity
is desirable, with the advantageous mechanical properties of the metal substrate preserved. The
necessary condition is good adhesion of the layer to the substrate.
Production of the silicate layers on the Ti6Al4V alloy substrate in two stages has been
planned. The Si–Ti sol was prepared as the sol applied directly on that metallic base, produced
from organic derivatives of silicon and titanium: Si(OC
2
H
5
)
4
and Ti(OC
3
H
7
)
4
. The series of sols
on the proper Si–Ca layer was prepared from the organic derivative of silicon Si(OC
2
H
5
)
4
and
inorganic of calcium CaCl
2
.2H
2
O, retaining the fixed mole ratio Si:Ca of 75:25 and changing the
concentration of the sols with addition of various volumes of the solvent.
The prepared sols were applied on the Ti
6
Al
4
V substrates with the dip-coating method, to
receive the coats with the double Si–Ti sublayer and a varied number of the proper Si–Ca layers.
The layers were fixed during heat processing at the temperature of 600°C in the argon
atmosphere.
The resulting samples were subjected to IR spectroscopic examinations, XRD tests and
scanning microscopy with EDX. XRD tests confirmed the amorphic nature of the layers heated
for 1 h, irrespective of the concentrations of the applied sols and the number of the layers. For
the samples heated for a longer time, the beginning of crystallisation of wollastonite was
observed. Observations of morphology of the surface of the samples showed that the resulting
coats are compact and have the float nature sized from ca. 5 to ca. 60 µm, and the multilayer
nature of the coat prevents opening of the clean substrate places of float cracking. X-ray
microanalysis showed that the proper coats include silicon and calcium, and the content of
calcium was lower than compared with the assumed value.
The thorough analysis of IR spectroscopic spectra was conducted for all the resulting
samples. Systematic shift of the bands was observed related to the change in the concentration of
the sols. The conducted analyses allowed to select the beneficial concentrations of the sols and
to optimise the process of their synthesis.
Keywords: silica layers; IR spectra; sol-gel method
Acknowledgment
This work was funded under project no. 11.11.160.767 at the AGH University of Science and Technology
in Krakow.
References
[1] M. Rokita, W. Mozgawa, A. Adamczyk, J. Mol. Str. 1070 (2014) 125.
[2] A. Adamczyk, M. Rokita, J. Mol. Str. 1114 (2016) 171.
Dostları ilə paylaş: |