15 “Polymer–Oxide” Micro-/Nanocomposites: Background and Promises
261
and operating in Bragg–Brentano (θ /2θ ) geometry. The XRD patterns were obtained
in the (2θ ) diffraction angle range 10–70 ◦ at 0.1 ◦ step.
The Netzsch 402C dilatometer (NETZSCH, Selb, Germany) with 3% accuracy
was used to study thermoexpansion characteristics, and a coefficient of thermal
expansion was measured in the temperature range of 25–110 ◦ C. The dilatometric
measurements were carried out along to normal the disc base. The heating rate used
during measurements was 10 ◦ C/min.
Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)
testing were made using Jupiter STA 449 F3 calorimeter by Netzsch (NETZSCH,
Selb, Germany). The same heating rate was used as in the dilatometric measurements.
The sample for dielectric studies was placed into thermostatic four-electrode cell
that enabled monitoring the sample thickness by means of additional air capacitor.
Measurements of the capacity and dielectric losses index of mentioned cell were
carried out at four fixed frequencies, f = 5, 10, 20, and 50 kHz in the temperature
range −180 ÷ 130 ◦ C. The automatic homemade equipment on the base of the
P5083 alternate current bridge was used for noted above measurements.
The PL (photoluminescence) and the PL excitation spectra were measured using
the spectrometric equipment SDL-2 M. The PL emission spectra were analyzed
using a single-grating (1200 grooves/mm) monochromator MDR-23 (linear dispersion 0.5 mm/nm) and DFS-12 (linear dispersion 1 mm/nm) equipped with FEU-100
and FEU-79 photomultipliers, respectively. The N 2 laser (λ ex = 337.1 nm), two
diode-pumped lasers (λ ex = 473 and 532 nm, respectively), and a xenon lamp
(DKsSh-150) were used as sources of PL excitation. The PL spectra were studied
as a function of the exciting radiation wavelength (λ ex ) and were analyzed over
a wide range of excitation and emission wavelengths (200–800 nm) and sample
temperatures (77–300 K).
The samples surfaces were scanned using electron microscopy instruments.
Figure 15.7 shows the typical SEM image (the sample 100-K 2 Eu(PO 4 )(MoO 4 ) was
taken as example). A lot of tightly packed grains of 5–10 μm of size can be seen over
there. Usually, they packed into large plates of ∼20–50 μm of size. Some crannies
are also seen between the plates (see, e.g., in the left part and in the center of Fig.
15.7). Other shape pieces also are on this image. They look like different inclusions
on the sample surface (e.g., see rectangles #3 and #4 on Fig. 15.2). Their sizes are in
10–200 nm range. Conglomerates of such particles form larger pieces of 2–10 μm
in size. The largest of them is near rectangle #5 on the Fig. 15.7.
The chemical element analysis was made for some zones of the samples when
SEM studies were carried out. For example, such zones are marked by rectangles
on Fig. 15.7. The average content of carbon (C) atoms (the range of its value is
74–76 at.% for all of the samples under study) and oxygen (O) atoms (25–23 at.%)
was predominant in zones of the plates (e.g., see zones 1 and 2) that allowed us
to conclude that the plates are blocks of the MCC matrix. The results of analysis
also pointed that mentioned above inclusions (e.g., see zones 3, 4, and 5) are the
areas where the oxide particles located, as their composition is close to the chemical
formulas of corresponding oxides. Average content of the chemical elements for the
261
and operating in Bragg–Brentano (θ /2θ ) geometry. The XRD patterns were obtained
in the (2θ ) diffraction angle range 10–70 ◦ at 0.1 ◦ step.
The Netzsch 402C dilatometer (NETZSCH, Selb, Germany) with 3% accuracy
was used to study thermoexpansion characteristics, and a coefficient of thermal
expansion was measured in the temperature range of 25–110 ◦ C. The dilatometric
measurements were carried out along to normal the disc base. The heating rate used
during measurements was 10 ◦ C/min.
Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)
testing were made using Jupiter STA 449 F3 calorimeter by Netzsch (NETZSCH,
Selb, Germany). The same heating rate was used as in the dilatometric measurements.
The sample for dielectric studies was placed into thermostatic four-electrode cell
that enabled monitoring the sample thickness by means of additional air capacitor.
Measurements of the capacity and dielectric losses index of mentioned cell were
carried out at four fixed frequencies, f = 5, 10, 20, and 50 kHz in the temperature
range −180 ÷ 130 ◦ C. The automatic homemade equipment on the base of the
P5083 alternate current bridge was used for noted above measurements.
The PL (photoluminescence) and the PL excitation spectra were measured using
the spectrometric equipment SDL-2 M. The PL emission spectra were analyzed
using a single-grating (1200 grooves/mm) monochromator MDR-23 (linear dispersion 0.5 mm/nm) and DFS-12 (linear dispersion 1 mm/nm) equipped with FEU-100
and FEU-79 photomultipliers, respectively. The N 2 laser (λ ex = 337.1 nm), two
diode-pumped lasers (λ ex = 473 and 532 nm, respectively), and a xenon lamp
(DKsSh-150) were used as sources of PL excitation. The PL spectra were studied
as a function of the exciting radiation wavelength (λ ex ) and were analyzed over
a wide range of excitation and emission wavelengths (200–800 nm) and sample
temperatures (77–300 K).
The samples surfaces were scanned using electron microscopy instruments.
Figure 15.7 shows the typical SEM image (the sample 100-K 2 Eu(PO 4 )(MoO 4 ) was
taken as example). A lot of tightly packed grains of 5–10 μm of size can be seen over
there. Usually, they packed into large plates of ∼20–50 μm of size. Some crannies
are also seen between the plates (see, e.g., in the left part and in the center of Fig.
15.7). Other shape pieces also are on this image. They look like different inclusions
on the sample surface (e.g., see rectangles #3 and #4 on Fig. 15.2). Their sizes are in
10–200 nm range. Conglomerates of such particles form larger pieces of 2–10 μm
in size. The largest of them is near rectangle #5 on the Fig. 15.7.
The chemical element analysis was made for some zones of the samples when
SEM studies were carried out. For example, such zones are marked by rectangles
on Fig. 15.7. The average content of carbon (C) atoms (the range of its value is
74–76 at.% for all of the samples under study) and oxygen (O) atoms (25–23 at.%)
was predominant in zones of the plates (e.g., see zones 1 and 2) that allowed us
to conclude that the plates are blocks of the MCC matrix. The results of analysis
also pointed that mentioned above inclusions (e.g., see zones 3, 4, and 5) are the
areas where the oxide particles located, as their composition is close to the chemical
formulas of corresponding oxides. Average content of the chemical elements for the