Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading
We investigated the effect of uniaxial pressure (0÷1000 bars) applied parallely to the ac electric field on dielectric properties of PLZT-x/65/35 (2≤x≤13) ceramics. There was revealed a significant effect of the external stress on these properties. The application of uniaxial pressure leads to the c...
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irk-123456789-1208332017-06-14T03:04:16Z Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading Pytel, K. Suchanicz, J. Livinsh, M. Sternberg, A. We investigated the effect of uniaxial pressure (0÷1000 bars) applied parallely to the ac electric field on dielectric properties of PLZT-x/65/35 (2≤x≤13) ceramics. There was revealed a significant effect of the external stress on these properties. The application of uniaxial pressure leads to the change of the peak intensity of the electric permittivity (ϵ), of the frequency dispersion as well as of the dielectric hysteresis. The peak intensity ϵ becomes diffused/sharpened and shifts to a higher/lower temperatures with increasing the pressure. It was concluded that the application of uniaxial pressure induces similar effects as increasing the Ti ion concentration in PZT system. We interpreted our results based on the domain switching processes under the action of combined electromechanical loading. Ми дослiдили вплив одновiсного тиску (0÷1000 bars), прикладеного паралельно до змiнного електричного поля, на властивостi керамiки PLZT-x/65/35 (2≤x≤13). Виявлено значний вплив зовнiшнього напруження на цi властивостi. Прикладання одновiсного тиску веде до змiни пiку iнтенсивностi електричної проникностi ("), частотної дисперсiї i дiелектричного гiстерезису. Пiк iнтенсивностi " стає розмитий/загострений i зсувається до вищих/нижчих температур з ростом тиску. Робиться висновок, що прикладання одновiсного тиску iндукує подiбнi ефекти як пiдвищення концентрацiї iонiв Ti в системi PZT. Ми iнтерпретуємо нашi результати на основi процесiв перемикання доменiв пiд дiєю комбiнованого електромеханiчного навантаження. 2013 Article Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading / K. Pytel, J. Suchanicz, M. Livinsh, A. Sternberg // Condensed Matter Physics. — 2013. — Т. 16, № 3. — С. 31706:1-10. — Бібліогр.: 8 назв. — англ. 1607-324X PACS: 77.84.Lf, 77.80.bg DOI:10.5488/CMP.16.31706 arXiv:1309.6126 http://dspace.nbuv.gov.ua/handle/123456789/120833 en Condensed Matter Physics Інститут фізики конденсованих систем НАН України |
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We investigated the effect of uniaxial pressure (0÷1000 bars) applied parallely to the ac electric field on dielectric properties of PLZT-x/65/35 (2≤x≤13) ceramics. There was revealed a significant effect of the external stress on these properties. The application of uniaxial pressure leads to the change of the peak intensity of the electric permittivity (ϵ), of the frequency dispersion as well as of the dielectric hysteresis. The peak intensity ϵ becomes diffused/sharpened and shifts to a higher/lower temperatures with increasing the pressure. It was concluded that the application of uniaxial pressure induces similar effects as increasing the Ti ion concentration in PZT system. We interpreted our results based on the domain switching processes under the action of combined electromechanical loading. |
| format |
Article |
| author |
Pytel, K. Suchanicz, J. Livinsh, M. Sternberg, A. |
| spellingShingle |
Pytel, K. Suchanicz, J. Livinsh, M. Sternberg, A. Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading Condensed Matter Physics |
| author_facet |
Pytel, K. Suchanicz, J. Livinsh, M. Sternberg, A. |
| author_sort |
Pytel, K. |
| title |
Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading |
| title_short |
Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading |
| title_full |
Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading |
| title_fullStr |
Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading |
| title_full_unstemmed |
Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading |
| title_sort |
dielectric properties of plzt-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading |
| publisher |
Інститут фізики конденсованих систем НАН України |
| publishDate |
2013 |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/120833 |
| citation_txt |
Dielectric properties of PLZT-x/65/35 (2 ≤ x ≤ 13) under mechanical stress, electric field and temperature loading / K. Pytel, J. Suchanicz, M. Livinsh, A. Sternberg // Condensed Matter Physics. — 2013. — Т. 16, № 3. — С. 31706:1-10. — Бібліогр.: 8 назв. — англ. |
| series |
Condensed Matter Physics |
| work_keys_str_mv |
AT pytelk dielectricpropertiesofplztx65352x13undermechanicalstresselectricfieldandtemperatureloading AT suchaniczj dielectricpropertiesofplztx65352x13undermechanicalstresselectricfieldandtemperatureloading AT livinshm dielectricpropertiesofplztx65352x13undermechanicalstresselectricfieldandtemperatureloading AT sternberga dielectricpropertiesofplztx65352x13undermechanicalstresselectricfieldandtemperatureloading |
| first_indexed |
2025-07-08T18:42:09Z |
| last_indexed |
2025-07-08T18:42:09Z |
| _version_ |
1837105288419737600 |
| fulltext |
Condensed Matter Physics, 2013, Vol. 16, No 3, 31706: 1–10
DOI: 10.5488/CMP.16.31706
http://www.icmp.lviv.ua/journal
Proceedings Paper
Dielectric properties of PLZT-x/65/35 (2 É x É 13)
under mechanical stress, electric field and
temperature loading
K. Pytel1, J. Suchanicz2∗, M. Livinsh3, A. Sternberg3
1 Institute of Technology, Pedagogical University, 2 Podchorazych St., 30–084 Krakow, Poland
2 Institute of Physics, Pedagogical University, 2 Podchorazych St., 30–084 Krakow, Poland
3 Institute of Solid State Physics, University of Latvia, 8 Kengaraga St., LV–1063 Riga, Latvia
Received October 23, 2012
We investigated the effect of uniaxial pressure (0÷1000 bars) applied parallely to the ac electric field on dielec-
tric properties of PLZT-x/65/35 (2 É x É 13) ceramics. There was revealed a significant effect of the external
stress on these properties. The application of uniaxial pressure leads to the change of the peak intensity of the
electric permittivity (ε), of the frequency dispersion as well as of the dielectric hysteresis. The peak intensity
ε becomes diffused/sharpened and shifts to a higher/lower temperatures with increasing the pressure. It was
concluded that the application of uniaxial pressure induces similar effects as increasing the Ti ion concentra-
tion in PZT system. We interpreted our results based on the domain switching processes under the action of
combined electromechanical loading.
Key words: ferroelectric, PLZT-x/65/35, dielectric properties, uniaxial pressure
PACS: 77.84.Lf, 77.80.bg
1. Introduction
Single crystals, ceramics, polymers and ceramic-polymer composites which show ferroelectric be-
havior are used in many applications in electronics and optics. A large number of applications of ferro-
electrics exploit dielectric, piezoelectric, pyroelectric and electro-optic properties. Ferroelectric crystals
are commonly used in many areas of science and technology. Possibilities of the practical use of these
ceramics are associated with their outstanding electro-mechanical properties. A very small amount of
dopants may be sufficient to have a noticeable effect on macroscopic properties of these technologically
important materials. Ferroelectrics can be modified not only by purposeful doping but also by impuri-
ties or by defects formed at high processing temperatures. Softening and hardening of ferroelectrics by
acceptor and donor doping are the key tools to control their electrical and mechanical properties. These
properties include e.g. switching and hysteresis behavior, frequency dispersion and nonlinearity of elec-
tromechanical properties. PZT ceramics can be doped with ions to form soft and hard lead zirconate
titanates. The soft one have a higher permittivity, larger electrical losses, higher piezoelectric coefficient
and are easy to polarize and depolarize. They can be used for applications requiring very high piezo-
electric properties. The hard one have a lower permittivity, smaller electrical losses, lower piezoelectric
coefficients and are more difficult to polarize and depolarize. They can be used for rugged applications
[1]. Ferroelectrics could be modified by substitutions of Pb
2+
ions in PZT ceramics by La
2+
one (i.e. PLZT).
For PLZT-x/65/35 with x É 6, a paraelectric to ferroelectric phase transition occurs as the temperature is
lowered through the Curie point Tc and a second structural transition occurs at a lower temperature Tt
∗
E-mail: sfsuchan@up.krakow.pl
© K. Pytel, J. Suchanicz, M. Livinsh, A. Sternberg, 2013 31706-1
http://dx.doi.org/10.5488/CMP.16.31706
http://www.icmp.lviv.ua/journal
K. Pytel et al.
[2]. For PLZT-x/65/35 with x Ê 7 no paraelectric to ferroelectric transition occurs as the temperature is
lowered through Tc and ceramic shows a broad peak in the low frequency dielectric constant, ε(T ) [3].
Compositions x/65/35 with x > 6 exhibits typical relaxor behaviors such as frequency-dependent electric
permittivity maximum, existence of polar nanoregions at temperatures above the diffuse phase transi-
tion point and broad distribution of relaxation times [4]. The incorporation of aliovalent lanthanum into
the lattice enhances the densification rates of the PZT ceramics, leading to pore-free homogeneous mi-
crostructures. In many device applications, ceramics are subjected to combined electric and stress fields,
so a better understanding of phenomena occurring under electromechanical loading is essential. In the
present study the results of dielectric properties measurements of PLZT ceramics with a Zr/Ti ratio of
65/35 and variable La content (2–13 at.%) under uniaxial pressure applied parallel to the ac electric field
were presented.
2. Experimental procedure
2.1. Material
PLZT-x/65/35with a different content of lanthanum powders were acquired by two-stage co-precipi-
tation method from mixed solution of inorganic salts ZrOCl2 ·8H2O, TiCl4, La(NO2)3 ·6H2O and Pb(NO3)2
well described in paper [5]. At the first stage, the hydroxypolymer of TiO2-ZrO2-La2O3 is obtained by co-
precipitation with 25% NH4OH from a mixed solution of the corresponding metallic salts. At the second
stage, PbOwas introduced into themixture of TiO2-ZrO2-La2O3. Ceramic sampleswere prepared by a two-
stage hot-pressing technology [5]. The first stage was performed at 1150÷1180◦C for 1 hour in vacuum
at pressure 200 MPa. The second stage was performed at 1150÷ 1200◦C for 1÷ 40 hours depending on
the size (15÷90mm diameter) at pressure 200 MPa in the air or in O2 rich atmosphere. As a result, high
density and transparent ceramics were obtained.
(a) (b)
(c) (d)
Figure 1. SEM image of the fracture surface of PLZT-x/65/35 ceramics (x = 2,6, 10 and 13).
31706-2
Dielectric properties of PLZT-x/65/35 (2 É x É 13)
2.2. Microstructure measurements
The scanning electron microscope (SEM) Hitachi S-4700, equipped with an energy dispersive X-ray
spectrometer (EDS) having Si(Li) X-ray detector, was used for the investigation of the microstructure of
ceramics. The EDS analysis was performed using the Noran-Vantage system.
2.3. Dielectric measurements
The dielectric measurements were carried out in a weak electric field (30 V/cm) using BM 595A LCR
meter in a temperature range from room temperature to 460
◦
C. The samples were previously electroded
by silver paste. The temperature of samples was controlled by a thermocouple with the accuracy of
±0.1◦C. Prior to the experiments, the samples were heated for at least 1h at about 500◦C to release both
internal strains and those at the electrode/sample interface. The temperature dependence of the per-
mittivity was measured during heating and cooling processes at the rate of l00
◦
C/h. Compressive stress
within the range of (0÷1000) bar was applied parallel to the measuring electric field with the use of a
lever and a weight.
3. Results and discussion
Figure 1 shows the cross-section morphological feature of PLZT-x/65/35 with x = 2, 6, 10 and 13. As
can be seen from this figure, dense and crack-free ceramics without second phases were sintered. The av-
erage grain size of the regular crystal-shape ceramics is ca. 5÷8 µm for PLZT-x/65/35with x = 2, 6,10 and
13. The crystalline boundaries are clearly observed. The EDS analyses completed for individual grains in
different compositions indicated a homogenous distribution of all elements in ceramics. Chemical analy-
sis of the obtained samples performed by emission microanalyzer for Pb, Zr, Ti and La agreed well with
the nominal composition of PLZT.
The temperature/frequency dependence of the electric permittivity for the pressure applied parallel
to the ac electric field for the PLZT ceramics analyzed are presented in figures 2–5. The main outcome
obtained from these dependences show that with an increase of pressure:
1. The ε(T ) maximum becomes more diffuse. The results in figure 2 reveal a remarkable reduction
of the temperature of the maximum dielectric permittivity (Tm) and an increase in the diffuseness
of the dielectric permittivity peak by increasing the La
3+
content on the Pb
2+
site. A further result
of the pressure application is the reduction of thermal hysteresis (inserts in figure 2). These can
suggest the character of the transformation change to the second order.
2. The temperature of ε(T ) maximum (Tc) shifts toward higher temperature of approximately
∂Tc/∂p = 5.2 ± 0.5◦C/kbar for PLZT-x/65/35 with x = 2 and downward toward lower tempera-
ture of approximately ∂Tc/∂p = −13.5 ± 0.5◦C/kbar, ∂Tc/∂p = −8.6 ± 0.5◦C/kbar and ∂Tc/∂p =
−9.7±0.5◦C/kbar for PLZT-x/65/35with x = 6, 10 and 13, respectively, on heating. The temperature
of ε(T )maximum (Tc) shifts toward higher temperature of approximately ∂Tc/∂p = 7.4±0.5◦C/kbar
for PLZT-x/65/35with x = 2 and downward toward lower temperature of approximately ∂Tc/∂p =
−19.5±0.5◦C/kbar, ∂Tc/∂p =−9.8±0.5◦C/kbar and ∂Tc/∂p =−12.7±0.5◦C/kbar, for PLZT-x/65/35
with x = 6, 10 and 13, respectively, on cooling. The up and down shifts are nearly linear in the range
of pressure from 0 to 1kbar for the analyzed PLZT-x/65/35 ceramics (x = 2, 6, 10 and 13) (figure 4
and table 1).
3. The maximum value of the electric permittivity decreases gradually with an increasing La
3+
con-
tent for PLZT-x/65/35 with x = 6, 10 and 13 (figure 4 and table 1).
4. The maximum value of the electric permittivity decreases gradually with an increasing applied
pressure for PLZT-x/65/35with x = 2, 6 and 10, and increases gradually with an increasing applied
pressure for PLZT-x/65/35 with x = 13. The maximum values of the electric permittivity change
approximately ∂εm/∂p =−16100±5/kbar, ∂εm/∂p =−3400±5/kbar, ∂εm/∂p =−260±5/kbar and
∂εm/∂p = −81± 5/kbar for PLZT-x/65/35 with x = 2, 6, 10 and 13, respectively, on heating. The
31706-3
K. Pytel et al.
0 100 200 300 400 500
0
10
20
30
40
50
60
70
0 100 200 300 400 500 600
0
10
20
30
40
50
60
70
0 100 200 300 400 500
0
10
20
30
40
50
60
70
cooling
heating
0 bar
e
(1
0
3
)
T [°C]
aPLZT 2/65/35
10 kHz heating
e
(1
0
3
)
T [°C]
0bar
100bar
200bar
300bar
400bar
600bar
800bar
cooling
heating
800 bar
e
(1
0
3
)
T [°C]
0 100 200 300 400 500
0
10
20
30
40
50
60
70
0 100 200 300 400 500 600
0
10
20
30
40
50
60
70
0 100 200 300 400 500
0
10
20
30
40
50
60
70
cooling
heating
0 bar
e
(1
0
3
)
T [°C]
bPLZT 6/65/35
10 kHz heating
e
(1
0
3
)
T [°C]
0bar
100bar
200bar
300bar
400bar
600bar
800bar
cooling
heating
800 bar
e
(1
0
3
)
T [°C]
0 100 200 300 400 500
0
5
10
15
0 100 200 300 400 500 600
0
5
10
15
20
25
30
0 100 200 300 400 500
0
5
10
15
cooling
heating
0 bar
e
(1
0
3
)
T [°C]
cPLZT 10/65/35
10 kHz heating
e
(1
0
3
)
T [°C]
0bar
100bar
200bar
300bar
400bar
600bar
800bar
cooling
heating
800 bar
e
(1
0
3
)
T [°C]
0 100 200 300 400 500
0
5
10
15
0 100 200 300 400 500 600
0
5
10
15
20
25
30
0 100 200 300 400 500
0
5
10
15
cooling
heating
0 bar
e
(1
0
3
)
T [°C]
PLZT 13/65/35
10 kHz heating
e
(1
0
3
)
T [°C]
0bar
100bar
200bar
300bar
400bar
600bar
800bar
d
cooling
heating
800 bar
e
(1
0
3
)
T [°C]
Figure 2. Temperature/pressure dependence of the electric permittivity ε of PLZT-x/65/35 ceramics with
x = 2 (a), 6 (b), 10 (c) and 13 (d) (on heating, f = 1 kHz). Inserts show the same on heating and cooling for
p = 0 bar and 800 bar, respectively.
maximum value of the electric permittivity changes approximately ∂εm/∂p = −13000 ± 5/kbar,
∂εm/∂p = −3400±5/kbar, ∂εm/∂p = −400±5/kbar and ∂εm/∂p = 120±5/kbar for PLZT-x/65/35
with x = 2, 6, 10 and 13, respectively, on cooling. The changes of maximal value of permittivity
caused by the uniaxial pressure show that shifts are nearly linear in the range of pressure from 0
to 1 kbar for all the PLZT ceramics analyzed.
31706-4
Dielectric properties of PLZT-x/65/35 (2 É x É 13)
5. The dielectric dispersion decreases with an increasing La
3+
content for PLZT-x/65/35 with x =
2, 6, 10 and 13. The values of the electric dispersion change approximately from ∂εm/∂ f = 955/kHz
at p = 0 bar to about 540/kHz at p = 1 kbar, from ∂εm/∂ f = 830/kHz at p = 0 bar to about 90/kHz at
p = 1 kbar, from ∂εm/∂ f = 39/kHz at p = 0 bar to about 18/kHz at p = 1 kbar, and from ∂εm/∂ f =
0.01/kHz at p = 0 bar to about 8/kHz at p = 1 kbar for PLZT-x/65/35 with x = 2, 6, 10 and 13,
respectively.
6. The dielectric dispersion decreases with an increasing applied pressure for PLZT-x/65/35 with
x = 2, 6 and 10.
7. Dielectric losses change in a way similar to dielectric constant. The maximum intensity of the tanδ
curve decreases, becomes more diffuse and shifts toward lower temperature for PLZT-x/65/35
with x = 2, 6, 10 and 13 (figure 3).
The samples, which are more sensitive to pressure are PLZT-x/65/35 with x = 6 (the highest ∂Tc/∂p
on cooling) and PLZT-x/65/35with x = 2 (the highest ∂εm/∂p on heating). The sample, which is alsomore
sensitive to the frequency of the measured electric field (the highest ∂εm/∂ f ) is PLZT-x/65/35 with x = 2
(figure 5 and table 1).
Table 1. ∂Tc/∂p , ∂εm/∂p and ∂εm/∂ f estimated for investigated materials.
Sample ∂Tc/∂p ∂εm/∂p ∂εm/∂ f (heating)
(heating/cooling) (heating/cooling) p = 0 bar/p = 1 kbar
PLZT 2/65/35 5.2/7.4±0.5◦C/kbar −16100/−13000±5/kbar 955/540/kHz
PLZT 6/65/35 −13.5/−19.5±0.5◦C/kbar −3400/−3400±5/kbar 830/90/kHz
PLZT 10/65/35 −8.6/−9.8±0.5◦C/kbar −260/−400±5/kbar 39/18/kHz
PLZT 13/65/35 −9.7/−12.7±0.5◦C/kbar 81/120±5/kbar 0/8/kHz
The changes in properties of ceramics under the mechanical load (0÷1000 bars) can be attributed to
the creation or annihilation of detects, an elastic change of distances between ions in the crystal structure
and to a change in the domain structure. It is difficult to estimate the contribution of each mechanism.
The contribution coming from the changes in the density of defects can be negligible because the changes
of the properties are reversible after heating to high temperature followed by cooling [1]. Changes in the
distance between ions can lead to the variations of phase transition temperature by changes of inter-
action constants or by changes of dipole moments. The phase transition temperature will increase or
decrease depending on which mechanism is predominant [6]. Changes in the domain structure, i.e., in-
duced domain wall movement and domain switching may be derived from applying a mechanical stress.
Mechanical load in the investigated materials is large enough to reduce the density of the domains in
the direction parallel to the stress by non-180° domain switching and to increase the density of the do-
main in perpendicular direction. This implies a decrease of the domain ordering in one direction and an
increase of the domain ordering in the opposite direction. Electric and elastic nanoregions in PLZT can
be reoriented by uniaxial pressure in the direction in which pressure is applied for PLZT-x/65/35 with
x >6. Nanoregions are forced in the new positions and their contribution to the electric permittivities is
smaller, and thus ε and tanδ decrease (figures 2–5). A further effect of the applied pressure can be an
increase in sizes of nanoregions and their combination into larger complexes, which results in a weaker
dielectric response. These effects can cause a narrowing distribution of relaxation time, which in turn
can lead to a suppression of dispersion in the frequency range used.
For a normal ferroelectric above the temperature of the phase transition (Tc), the electric permittivity
falls off with temperature according to:
ε= ε0 + C
T −T0
' C
T −T0
, (1)
where C is the Curie constant and T0 is the Curie-Weiss temperature. Both C and T0 decrease with an
increasing pressure. It was found that for our samples (p = 0 bar), ε starts to obey the Curie-Weiss law
31706-5
K. Pytel et al.
0 100 200 300 400 500
0,00
0,05
0,10
0,15
0,20
ta
n
d
PLZT 2/65/35
10 kHz heating
T [°C]
0bar
100bar
200bar
300bar
400bar
600bar
800bar
a
0 100 200 300 400 500
0,00
0,05
0,10
0,15
0,20
b
ta
n
d
PLZT 6/65/35
10 kHz heating
T [°C]
0bar
100bar
200bar
300bar
400bar
600bar
800bar
0 100 200 300 400 500
0,00
0,05
0,10
0,15
0,20
c
ta
n
d
PLZT 10/65/35
10 kHz heating
T [°C]
0bar
100bar
200bar
300bar
400bar
600bar
800bar
0 100 200 300 400 500
0,00
0,05
0,10
0,15
0,20
d
ta
n
d
PLZT 13/65/35
10 kHz heating
T [°C]
0bar
100bar
200bar
300bar
400bar
600bar
800bar
Figure 3. Temperature/pressure dependence of the dielectric loss of PLZT-x/65/35 ceramics with x = 2
(a), 6 (b), 10 (c) and 13 (d) on heating ( f = 10 kHz).
at temperatures higher than Tm (e.g. temperature at which ε reaches the maximum). Deviation degree
of ε from the Curie-Weiss law can be defined by ∆Tcm as follows: ∆Tcm = Tdev −Tm, where Tdev is the
temperature, at which ε starts to obey the Curie-Weiss law. It is found that for p = 0 bar, ∆Tcm = 5.5◦C,
14
◦
C, 18
◦
C, and 23
◦
C for PLZT-x/65/35with x = 2, 8, 10 and 13, respectively. For p = 800 bar:∆Tcm = 2.5◦C,
31706-6
Dielectric properties of PLZT-x/65/35 (2 É x É 13)
0 100 200 300 400 500 600 700 800
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
a
PLZT 2/65/35
10 kHz
p (bar)
T
X m
-T
0 m
(o
C
)
heating
cooling
-55
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
e
X m
-
e
0 m
(x
1
0
3
)
0 100 200 300 400 500 600 700 800
-40
-30
-20
-10
0
10
20
30 b heating
cooling
PLZT 6/65/35
10 kHz
p (bar)
T
X m
-T
0 m
(o
C
)
-20
-15
-10
-5
0
5
e
X m
-
e
0 m
(x
1
0
3
)
0 100 200 300 400 500 600 700 800
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
c
PLZT 10/65/35
10 kHz
p (bar)
T
X m
-T
0 m
(o
C
)
heating
cooling
-2,0
-1,8
-1,6
-1,4
-1,2
-1,0
-0,8
-0,6
-0,4
-0,2
0,0
0,2
0,4
0,6
e
X m
-
e
0 m
(x
1
0
3
)
0 100 200 300 400 500 600 700 800
-20
-10
0
10
20
30
heating
cooling
PLZT 13/65/35
10 kHz
p (bar)
T
X m
-T
0 m
(o
C
)
d
-1,0
-0,8
-0,6
-0,4
-0,2
0,0
0,2
0,4
0,6
0,8
e
X m
-
e
0 m
(x
1
0
3
)
Figure 4. Shift of the transition temperature and change of themaximal value of permittivity as a function
of pressure of the T X
m −T 0
m and ε
X
m −ε0
m of PLZT-x/65/35 ceramics with x = 2 (a), 6 (b), 10 (c) and 13 (d)
on heating and cooling. T X
m and T 0
m is the transition temperature at pressure X and 0 bar, respectively.
εX
m and ε
0
m is maximal value of the permittivity at the pressure X and 0 bar, respectively.
13
◦
C, 26
◦
C, and 32
◦
C for PLZT-x/65/35 with x = 2, 8, 10 and 13, respectively. This implies that the applied
uniaxial pressure weakens (for PLZT-x/65/35 with x = 2 and 8) or enhances (for PLZT-x/65/35 with
x = 10 and 13) the diffuse phase transformation behavior.
A modified expression of Curie-Weiss law explains the diffuseness of ferroelectric phase transition
described by:
1
ε
− 1
εm
= (T −Tm)γ
C∗ , (2)
where γ and C∗
are constants, γ value is between 1 and 2. The limiting value γ=1 reduces the equation
31706-7
K. Pytel et al.
0 100 200 300 400 500 600
0
10
20
30
40
50
60
70
80
0 100 200 300 400 500 600
0
10
20
30
40
50
60
70
80
PLZT 2/65/35
p = 0 bar
heating
e
(1
0
3
)
T [°C]
frequency
increase
0,1-20 kHz
a
a
frequency
increase
0,1-20 kHz
PLZT 2/65/35
p = 800 bar
heating
e
(1
0
3
)
T [°C]
0 100 200 300 400 500 600
0
10
20
30
40
50
60
70
80
0 100 200 300 400 500 600
0
10
20
30
40
50
60
70
80
PLZT 6/65/35
p = 0 bar
heating
e
(1
0
3
)
T [°C]
frequency
increase
0,1-20 kHz
b
b
frequency
increase
0,1-20 kHz
PLZT 6/65/35
p = 800 bar
heating
e
(1
0
3
)
T [°C]
0 100 200 300 400 500 600
0
5
10
15
0 100 200 300 400 500 600
0
5
10
15
PLZT 10/65/35
p = 0 bar
heating
e
(1
0
3
)
T [°C]
frequency
increase
0,1-20 kHz
c
c
frequency
increase
0,1-20 kHz
PLZT 10/65/35
p = 800 bar
heating
e
(1
0
3
)
T [°C]
0 100 200 300 400 500 600
0
5
10
15
0 100 200 300 400 500 600
0
5
10
15
PLZT 13/65/35
p = 0 bar
heating
e
(1
0
3
)
T [°C]
frequency
increase
0,1-20 kHz
d
d
frequency
increase
0,1-20 kHz
PLZT 13/65/35
p = 800 bar
heating
e
(1
0
3
)
T [°C]
Figure 5. Temperature/frequency dependence of electric permittivity for PLZT-x/65/35 ceramics (x =
2, 6, 10 and 13) on heating at p = 0 bars (top) and p = 800 bars (bottom).
to normal Curie-Weiss law (for classical ferroelectrics) and γ = 2 reduces the equation to quadratic (for
relaxor ferroelectrics) [7]. The dependence of ln(1/ε−1/εm) on ln(T −Tm) according to equation (2) for
the analyzed ceramics shows the slope of the curve giving the diffuseness constant γ. A nearly linear
correlation is observed on heating for f = 10 kHz and for p = 0 bar there is obtained γ = 1.7, γ = 1.1,
γ= 1.7 and, γ= 1.2 for PLZT-x/65/35, x = 2, 6, 10 and 13, respectively. However, for higher pressures, γ
31706-8
Dielectric properties of PLZT-x/65/35 (2 É x É 13)
increases indicating that a classical ferroelectric seems to change to a relaxor one. For p = 800 bar there
is obtained γ= 1.9, γ= 1.7, γ= 1.9, γ= 1.9 for PLZT-x/65/35, x = 2, 6, 10 and 13, respectively.
PLZT ceramics have perovskite-type ABO3 structurewith Zr/Ti ions located at the place of the B cations
and Pb/La ions occupying the A-sites. Pb ions displace in the direction of smaller Ti ions. The positive
charge of the Ti ion, whose atomic radius is smaller than that of Zr ion, is better screened by surrounding
oxygen ions and allows a shorter Pb-Ti distance [8]. The incorporation of Ti ions instead of Zr to PbZrO3
leads to an increase of the phase transition temperature in PZT system. Due to a smaller ionic radius of
the Ti ion than Zr one, the material was subjected to compressive stress with an increased Ti content.
This could explain why the compressive stress induces a similar effect as that from an increase of the
concentrations of Ti ions in PZT.
4. Conclusions
High density PLZT-x/65/35 (x = 2, 6, 10 and 13) ceramics with the average grain size of ca. 5÷8 µm
was obtained by a two-stage hot-pressing technology. The effect of the uniaxial pressure on dielectric re-
sponse of these ceramics has been examined. There is a diffuse transition in the examined PLZT ceramics,
and the diffuseness constant γ depends on pressure. With an increase of pressure, the phase transition
temperature, the frequency dispersion and the thermal hysteresis change, and the dielectric behavior
characteristics spread. Applying uniaxial pressure or increasing the Ti content in a PZT system would
induce similar effects.
References
1. Suchanicz J., Kim-Ngan N.T., Konieczny K., Jankowska-Sumara I., Balogh A.G., J. Appl. Phys., 2011, 109, 104105;
doi:10.1063/1.3585826.
2. Simpson G., Keve E., Ferroelectrics, 1976, 12, 229–231; doi:10.1080/00150197608241435.
3. Carl K., Geisen K., Proc. IEEE, 1973, 61, 967–974; doi:10.1109/PROC.1973.9186.
4. Kamba S., Bovtun V., Petzelt J., Rychetsky I., Mizaras R., Brilingas A., Banys J., Grigas J., KosecM., J. Phys.: Condens.
Matter, 2000, 12, 497–519; doi:10.1088/0953-8984/12/4/309.
5. Dambekalne M., Antonova M., Livinsh M., Garbarz-Glos B., Smiga W., Sternberg A., J. Eur. Cer. Soc., 2006, 26,
2963–2966; doi:10.1016/j.jeurceramsoc.2006.02.012.
6. Suchanicz J., Wojcik K., Mat. Sci. Eng. B, 2003, 104, 31–35; doi:10.1016/S0921-5107(03)00263-0.
7. Uchino K., Nomura S., Ferroelectrics, 1982, 44, 55–61; doi:10.1080/00150198208260644.
8. Kuzmin A., Purans J., Sternberg A., In: Proceeding of the NATO Advanced Research Workshop “Defects and
Surface-Induced Effects in Advanced Perovskites” (Jurmala, 1999), Vol. 77, Kluwer Academic Publishers, Dor-
drecht, 2000, p. 145–150.
31706-9
http://dx.doi.org/10.1063/1.3585826
http://dx.doi.org/10.1080/00150197608241435
http://dx.doi.org/10.1109/PROC.1973.9186
http://dx.doi.org/10.1088/0953-8984/12/4/309
http://dx.doi.org/10.1016/j.jeurceramsoc.2006.02.012
http://dx.doi.org/10.1016/S0921-5107(03)00263-0
http://dx.doi.org/10.1080/00150198208260644
K. Pytel et al.
Дiелектричнi властивостi PLZT-x/65/35 (2 É x É 13) пiд
впливом механiчного напруження, електричного поля i
температурного навантаження
К. Питель1, Я. Суханич2,М. Лiвiнш3, А. Стернберг3
1 Iнститут технологiї, Педагогiчний унiверситет, 30–084 Кракiв, Польща
2 Iнститут фiзики, Педагогiчний унiверситет, 30–084 Кракiв, Польща
3 Iнститут фiзики твердого тiла, Унiверситет Латвiї, 1063 Рига, Латвiя
Ми дослiдили вплив одновiсного тиску (0÷ 1000 bars), прикладеного паралельно до змiнного електри-
чного поля, на властивостi керамiки PLZT-x/65/35 (2 É x É 13). Виявлено значний вплив зовнiшнього
напруження на цi властивостi. Прикладання одновiсного тиску веде до змiни пiку iнтенсивностi електри-
чної проникностi (ε), частотної дисперсiї i дiелектричного гiстерезису. Пiк iнтенсивностi ε стає розми-
тий/загострений i зсувається до вищих/нижчих температур з ростом тиску. Робиться висновок, що при-
кладання одновiсного тиску iндукує подiбнi ефекти як пiдвищення концентрацiї iонiв Ti в системi PZT.Ми
iнтерпретуємо нашi результати на основi процесiв перемикання доменiв пiд дiєю комбiнованого еле-
ктромеханiчного навантаження.
Ключовi слова: сегнетоелектрик, PLZT-x/65/35, дiелектричнi властивостi, одновiсний тиск
31706-10
Introduction
Experimental procedure
Material
Microstructure measurements
Dielectric measurements
Results and discussion
Conclusions
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