Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals
The comparative experimental analysis of polarization reversal kinetics in conventional homogeneous triglycine sulfate (NH₂ CH₂ COOH)₃ ˙ H₂SO₄; TGS) and relaxor strontium barium niobate (Sr₀.₆₁Ba₀.₃₉Nb₂O₆; SBN) crystals have been performed in a broad range of measurement conditions. The experimental...
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irk-123456789-1208312017-06-14T03:03:36Z Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals Matyjasek, K. Orłowski, M. The comparative experimental analysis of polarization reversal kinetics in conventional homogeneous triglycine sulfate (NH₂ CH₂ COOH)₃ ˙ H₂SO₄; TGS) and relaxor strontium barium niobate (Sr₀.₆₁Ba₀.₃₉Nb₂O₆; SBN) crystals have been performed in a broad range of measurement conditions. The experimental data have been collected from microscopic observation of the domain structure, switching current and D-E hysteresis loop registration. The hysteresis loop and dielectric spectra has a strong link to the configuration of ferroelectric microdomains. The domain structure dynamics was examined by the nematic liquid crystal (NLC) method. Здiйснено порiвняльний експериментальний аналiз оборотної кiнетики поляризацiї в стандартному однорiдному кристалi триглiцин сульфату (NH₂ CH₂ COOH)₃ ˙ H₂SO₄; TGS) i релаксорному кристалi стронцiй барiєвого нiобату (Sr₀.₆₁Ba₀.₃₉Nb₂O₆; SBN) в широкiй областi вимiрювальних умов. Експериментальнi данi були зiбранi з мiкроскопiчного спостереження доменної структури, струмовового перемикання i реєстрацiї петлi гiстерезису D ¡ E. Петля гiстерезису i дiелектричнi спектри мають сильний зв’язок з конфiгурацiєю сегнетоелектричних мiкродоменiв. Динамiка доменної структури вивчалася методом не-матичного рiдкого кристалу (NLC). 2013 Article Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals / K. Matyjasek, M. Orłowski // Condensed Matter Physics. — 2013. — Т. 16, № 3. — С. 31704:1–6. — Бібліогр.: 15 назв. — англ. 1607-324X PACS: 77.80.Dj, 77.80.Fm, 77.84.Dy DOI:10.5488/CMP.16.31704 arXiv:1309.6092 http://dspace.nbuv.gov.ua/handle/123456789/120831 en Condensed Matter Physics Інститут фізики конденсованих систем НАН України |
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The comparative experimental analysis of polarization reversal kinetics in conventional homogeneous triglycine sulfate (NH₂ CH₂ COOH)₃ ˙ H₂SO₄; TGS) and relaxor strontium barium niobate (Sr₀.₆₁Ba₀.₃₉Nb₂O₆; SBN) crystals have been performed in a broad range of measurement conditions. The experimental data have been collected from microscopic observation of the domain structure, switching current and D-E hysteresis loop registration. The hysteresis loop and dielectric spectra has a strong link to the configuration of ferroelectric microdomains. The domain structure dynamics was examined by the nematic liquid crystal (NLC) method. |
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Matyjasek, K. Orłowski, M. |
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Matyjasek, K. Orłowski, M. Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals Condensed Matter Physics |
| author_facet |
Matyjasek, K. Orłowski, M. |
| author_sort |
Matyjasek, K. |
| title |
Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals |
| title_short |
Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals |
| title_full |
Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals |
| title_fullStr |
Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals |
| title_full_unstemmed |
Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals |
| title_sort |
comparison of polarization switching in ferroelectric tgs and relaxor sbn crystals |
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Інститут фізики конденсованих систем НАН України |
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2013 |
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http://dspace.nbuv.gov.ua/handle/123456789/120831 |
| citation_txt |
Comparison of polarization switching in ferroelectric TGS and relaxor SBN crystals / K. Matyjasek, M. Orłowski // Condensed Matter Physics. — 2013. — Т. 16, № 3. — С. 31704:1–6. — Бібліогр.: 15 назв. — англ. |
| series |
Condensed Matter Physics |
| work_keys_str_mv |
AT matyjasekk comparisonofpolarizationswitchinginferroelectrictgsandrelaxorsbncrystals AT orłowskim comparisonofpolarizationswitchinginferroelectrictgsandrelaxorsbncrystals |
| first_indexed |
2025-07-08T18:41:54Z |
| last_indexed |
2025-07-08T18:41:54Z |
| _version_ |
1837105274863747072 |
| fulltext |
Condensed Matter Physics, 2013, Vol. 16, No 3, 31704: 1–6
DOI: 10.5488/CMP.16.31704
http://www.icmp.lviv.ua/journal
Proceedings Paper
Comparison of polarization switching in ferroelectric
TGS and relaxor SBN crystals
K. Matyjasek, M. Orłowski
Institute of Physics, Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of
Technology, Al. Piastów 48, 70–310 Szczecin, Poland
Received February 10, 2013
The comparative experimental analysis of polarization reversal kinetics in conventional homogeneous triglycine
sulfate ((NH2CH2COOH)3·H2SO4; TGS) and relaxor strontium barium niobate (Sr0.61Ba0.39Nb2O6; SBN) crystalshave been performed in a broad range of measurement conditions. The experimental data have been collected
frommicroscopic observation of the domain structure, switching current andD−E hysteresis loop registration.
The hysteresis loop and dielectric spectra have a strong link to the configuration of ferroelectric microdomains.
The domain structure dynamics was examined by the nematic liquid crystal (NLC) method.
Key words: polarization switching, ferroelectric domain, hysteresis loop, TGS, relaxor, SBN
PACS: 77.80.Dj, 77.80.Fm, 77.84.Dy
1. Introduction
Most of the ferroelectrics applications (including nonvolatile memories and a broad range of elec-
tronic, optical and acoustic devices) require control of the local polarization state. Thus, it is critical
to understand the process of polarization switching [1]. In this report, the effects of microstructure of
domains (point defects) on the ferroelectric properties are established experimentally in rather differ-
ent classes of ferroelectric materials, in well studied conventional ferroelectrics TGS and SBN relaxor
crystals. Despite its complicated chemical and crystallographic form, TGS exhibit a wide range of fea-
tures indispensable for understanding very basic features of the mechanism of polarization switching
[2]. Compared to conventional TGS, a unique property of relaxor SBN is the appearance of a very broad
and frequency-dependent dielectric anomaly near the ferroelectric phase transition [3]. The dielectric
properties of relaxors can be attributed to the development of quenched random fields associated with
a compositional/structural disorder [4]. Microscopic studies of the switching process in conjunction with
electric measurements allowed us to establish a relationship between local properties of the domain
dynamics and macroscopic responses such as polarization hysteresis loop , switching current and dielec-
tric permittivity measurements. The microscopic features of 180 degree domain wall dynamics, in low
electric fields, were investigated by NLC method. The switching current transients have been analyzed
by Kolmogorov-Avrami-Ishibashi (KAI) model based on the classical theory of nucleation and domain
growth [5].
2. Experimental methodology
To observe the optically indistinguishable 180
◦
domain walls in the both crystals, the NLC mixture
of p-methoxybenzylidene-p-n-butylaniline (MBBA) and pethoxybenzylidene-p-n-butylaniline (EBBA) was
used. Plateled-shaped samples of TGS and SBN were cut perpendicularly to the polar axis. A cover glass
© K. Matyjasek, M. Orłowski, 2013 31704-1
http://dx.doi.org/10.5488/CMP.16.31704
http://www.icmp.lviv.ua/journal
K. Matyjasek, M. Orłowski
coated with a conducting layer of SnO2 was used to observe the domain pattern evolution during polar-
ization reversal in an electric field. The regions, where the domain reorientation still occurs, look darker
because in these regions an electrohydrodynamic instability, particularly dynamic scattering, takes place
[6]. Hysteresis loops (D −E dependence) were recorded with a modified Sawyer-Tower circuit by apply-
ing an ac-field of 50 Hz. The switching currents were measured by applying square-wave electric pulses
(two positive pulses followed by two negative ones) amplified with a Kepco bipolar amplifier. Dielec-
tric permittivity dependence on temperature and frequency was measured by HP 4284A LCR meter. The
electrical measurements were carried out with air-drying silver paste as electrodes.
3. Results and discussion
The ability to reverse their polarization state in ferroelectric materials under the application of an
electric field determines their characteristic electric displacement – electric field (D −E ) hysteresis loop.
Figure 1 shows the shape of hysteresis loop (H-L) for TGS [figure 1 (a)] and SBN [figure 1 (b)].
The measurement of H-L in a broad range of ac-electric field shows that the relaxor SBN does not
have a definite coercive field. At a low electric field, H-L has a nearly square shape relative to D −E axis,
similar to the one observed for TGS crystal, indicating an abrupt change of the polarization orientation.
At higher E , the H-L for SBN becomes more slanted. It means that the slowly switching regions being
initially frozen, become activated and participate in the polarization reversal process.
The presence and the change of configuration of the domains determines the polarization hysteresis.
An essential difference between the domain dynamics is observed in normal homogeneous ferroelectric
TGS and relaxor SBN crystals. In both type of crystals, the nucleation of ferroelectric domains takes place
when the applied field exceeds a critical nucleation threshold (coercive field), which is subject to regional
variation for defects. Figure 2 (a)–(d) shows a series of video frames illustrating the domain pattern evo-
lution in TGS crystal starting with a single domain state in the negative electric field of 0.4 kVcm
−1
.
This field is high enough to complete the domain switching in the entire volume of the crystal sam-
ple. The polarization switching takes place through inhomogeneous nucleation process and anisotropic
growth of the domains. The growth of the existing domains is more favorable than the creation of new
ones. Thus, the nucleated domains expand with little or no resistance under an electric field and start
to coalesce into large ones accompanied by a decrease of the domain density. The region where inten-
sive nucleation takes place becomes larger on increasing the electric field [figure 2 (e)]. In a high electric
field, the density of the domain nuclei arranged in rows and the number of rows per unit length increase,
so that optically they become indistinguishable [see figure 2 (f)]. The inhomogeneous distribution of the
domain nuclei during switching is a result of non-uniform internal field distribution, which has been at-
tributed to the defects in the bulk of the crystal. A more homogeneous distribution of the domains during
switching has been observed in positive electric fields , as shown in figures 2 (g) and 2 (h).
Evolution of the domain structure is more complex in SBN relaxor crystal. Figure 3 illustrates the
domain pattern evolution in SBN, starting with a single domain state, in the electric field of 2.8 kVcm
−1
.
This field is high enough to complete the micro-scale domain switching in the entire volume of the
Figure 1. The family of hysteresis loop obtained by applying ac-electric field of 50 Hz at room temperature
for (a) TGS and (b) SBN crystal sample.
31704-2
Polarization switching in TGS and SBN
Figure 2. The domain pattern evolution observed in TGS crystal sample during switching process in nega-
tive electric field of 0.4 kVcm
−1
(applied at t = 0). Time from themoment of applying E in [s] (a) 0.2; (b) 0.4;
(c) 0.8; (d) 1.8; Distribution of domains in: negative E in [kVcm−1
] (e) 0.5; (f) 0.7; positive E (g) 0.4; (h) 0.7.
sample, because a further increase of the electric field does not induce any domain switching. Unlike the
TGS crystals, in relaxor SBN the creation of new domains is more favorable than their growth. The nucle-
ation process continues to take place during almost the whole polarization reversal process, at a constant
electric field. The specific mechanism of nucleation in SBN could be interpreted in terms of a wide
distribution of activation energies for nucleation resulting from the local structural irregularities [7, 8].
The fast polarization switching process was investigated by measuring the switching currents in re-
sponse to the square wave electric pulses. The switching current i (t ) was obtained by subtracting the
non-switching current from a full current. The rate of polarization switching at constant E can be formed
by integration of i (t ) from t = 0 to the instant t . The results for TGS are presented in figure 4 and for SBN
in figure 5.
Figure 3. Domain pattern evolution observed in SBN crystal sample during switching in the positive elec-
tric field of 2.8 kVcm
−1
. (a) — initial single domain state. Time from the moment of applying E in [s];
(b)— 0.2; (c)— 0.4; (d)— 0.6; (e)— 0.8; (f)— 1; (g)— 3.8; (h)— shows the domain pattern obtained after
applying the negative electric field of 2.8 kVcm
−1
.
31704-3
K. Matyjasek, M. Orłowski
Figure 4. Switching currents (a) and switching polarization (b) versus time for TGS crystal sample. The
polarization data were fitted with Avrami function (solid curves).
For TGS crystal, the saturated polarization is independent of the applied field. In relaxor SBN crystal,
the switched polarization increases with the electric field strength, but does not saturate. It means that
there are slowly switching regions that do not contribute to the switching current signals even in E > Ec
(coercive field). This should be related to the pinning effect of the domain walls resulting from a disorder
structure of SBN crystal [9].
The traditional model used in describing the switching kinetics of ferroelectrics, called the Kolmo-
gorov-Avrami-Ishibashi (KAI) model, is based on the classical statistical theory of nucleation and unre-
stricted domain growth [5]. Microscopic observation has revealed that, in the high electric field range
in which electrical measurements were carried out, the density of the domain nuclei is so high that the
linear dimension of the sample is much larger than the distance between the nuclei, as it was assumed
in the idealized KAI model. The KAI theory gives the polarization change P (t ) (called Avrami function)
as P (t ) = P0
{
1−exp[− (t/t0)n]
}
, where n and t0 are the effective dimensionality and characteristic time,
respectively, and P0 is the switchable polarization. The effective dimensionality n is related to the actual
growth dimension d of the domain walls and the mechanisms for nucleation. One-dimensional growth
(d = 1) implies plate-like domains with the walls moving in one direction perpendicular to the ferro-
electric axis. Two-dimensional growth (d = 2) occurs when the nuclei are considered to be cylinders [as
shown in figure 2 (g)]. The exponent n depends on the assumed nucleation scenario. The constant nucle-
ation rate corresponds to the exponent n = d +1, whereas the case of one-step nucleation leads to n = d .
In figures 4 and 5, the experimental data were fitted by the Avrami function. The results for TGS crystal
Figure 5. Switching currents and switched polarization versus time for SBN crystal sample. The polariza-
tion data were fitted with Avrami function (dashed curves).
31704-4
Polarization switching in TGS and SBN
show that the effective dimension n is lower than 2 and the characteristic time t0 decreases with an in-
creasing field. The switching kinetics is in reasonable agreement with that predicted theoretically for a
continuous nucleation case, indicating a one-dimensional growth of domains. Microscopic observations
[see figure 2 (h)] revealed that a one-dimensional growth in the high electric field range is a result of a
particular distribution of the domain nuclei arranged in rows. From the image analysis of the domain
growth pattern in TGS, it has been found that the nucleation rates (especially in the high field range),
as well as the velocities of domain walls do not stay constant throughout the switching process. In such
a case, the non-integer value of dimensionality n is typically obtained [10]. The retardation behavior in
such real physical conditions have been explained through polarization process with a broad distribu-
tion (Gaussian distribution) of characteristic domain growth times [11], or the Lorentzian distribution of
logarithmic switching times [12].
Although fitting curves (Avrami function) have given a good fitting quality for SBN crystal (figure 5),
the KAI model is not applicable to the polarization reversal of SBN crystal. Note that the n value less than
1 is not physically reasonable according to the KAImodel, since the growth dimensionality could never be
less than 1. A fundamental difference in the switching process is revealed in SBN, and may be accounted
for by the slow inhomogeneous domain growth in the presence of random pinning fields characteristic
of relaxor ferroelectrics [4].
The domain walls have a considerable effect on the total dielectric response of ferroelectric materials
[13]. Dielectric constants for TGS and SBN samples were measured versus temperature and the essential
results are presented in figure 6.
Figure 6. Temperature dependences of dielectric constants measured at different frequencies for: (a) —
TGS; (b)— SBN crystal sample.
The dielectric constant of the TGS exhibits a sharp, narrow peak at the phase transition temperature
Tc, and the width at half maximum is ∼ 2 K. By contrast, the relaxor SBN crystal exhibits very broad and
frequency-dependent dielectric anomaly, and the width at half maximum is ∼ 20÷ 40 K. The composi-
tional disorder in SBN could play an important role on the phase transition broadening assuming the
formation of the polar regions with locally different Curie temperature TC [14]. Note that a nanopolar
structure and local ferroelectricity have been revealed by piezoresponse force microcopy technique well
beyond the phase transition temperature in SBN crystal [15].
4. Conclusions
The results demonstrate important differences in the polarization switching mechanism in conven-
tional ferroelectric TGS and relaxor SBN crystals. It was shown that the domain growth is significant for
TGS. In relaxor SBN crystal, the polarization reversal takes place mostly by nucleation of the domains.
Thus, the KAI model of switching , based on statistics of domain coalescence, can be applied only to TGS
crystals. The observed complexity of the domain structure in relaxor SBN crystal could be understood in
terms of a slow inhomogeneous domain growth in the presence of random pinning fields, which give rise
to decelerated dynamics of domain walls.
31704-5
K. Matyjasek, M. Orłowski
Acknowledgements
The authors would like to thank Dr. L. Ivleva from Russian Academy of Sciences in Moscow for pro-
viding SBN samples.
References
1. Soergel E., Appl. Phys. B, 2005, 81, 729; doi:10.1007/s00340-005-1989-9.
2. Nakatani N., Ferroelectrics, 2011, 413, 238; doi:10.1080/00150193.2011.554269.
3. Dec J., Kleemann W., Woike Th., Pankrath R., Eur. Phys. J. B, 2000, 14, 627; doi:10.1007/s100510051071.
4. Kleemann W., J. Mater. Sci., 2006, 41, 129; doi:10.1007/s10853-005-5954-0.
5. Ishibashi Y., Takagi Y., J. Phys. Soc. Jpn., 1971, 31, 506; doi:10.1143/JPSJ.31.506.
6. Tikhomirova N.A., Dontsova L.J., Pikin S.A., Shuvalov L.A., JETP Lett., 1979, 29, 34.
7. Gladkii V.V., Kirikov V.A., Volk T.R., Ivleva L.I., Ferroelectrics, 2003, 285, 275; doi:10.1080/00150190390206112.
8. Matyjasek K., Wolska K., Rogowski R. Z, Kaczmarek S. M., Ivleva L. I., Ferroelectrics, 2011, 413, 311;
doi:10.1080/00150193.2011.531212.
9. Glass A.M., J. Appl. Phys., 1969 , 40, 4699; doi:10.1063/1.1657277.
10. Matyjasek K., J. Phys. D: Appl. Phys., 2001, 34, 2211; doi:10.1088/0022-3727/34/14/317.
11. Rogowski R. Z., Matyjasek K., Jakubas R., J. Phys. D: Appl. Phys., 2005, 38, 4145; doi:10.1088/0022-3727/38/23/001.
12. Jo J.Y., Han H.S., Yoon J.G., Song T.K., Kim S.H., Noh T.W., Phys. Rev. Lett., 2007, 99, 267602;
doi:10.1103/PhysRevLett.99.267602.
13. Lines M.E., Glass A.M., Principles and Applications of Ferroelectrics and Related Materials, Oxford University
Press, Oxford, 2001.
14. Bokov A.A. , Ye, Z.-G., J. Mater. Sci., 2006, 41, 31; doi:10.1007/s10853-005-5915-7.
15. Liu X.Y., Liu Y.M., Takekawa S., Kitamura K., Ohuchi F.S., Li J.Y., J. Appl. Phys., 2009, 106, 124106;
doi:10.1063/1.3273481.
Порiвняння перемикання поляризацiї в
сегнетоелектричному TGS i релаксорному SBN кристалах
К.Матиясек,М. Орловскi
Iнститут фiзики, факультет механiчної iнженерiї i мехатронiки,
Захiдно-померанський технологiчний унiверситет,Щецiн, Польща
Здiйснено порiвняльний експериментальний аналiз оборотної кiнетики поляризацiї в стандартному
однорiдному кристалi триглiцин сульфату ((NH2CH2COOH)3·H2SO4; TGS) i релаксорному кристалi строн-
цiй барiєвого нiобату (Sr0.61Ba0.39Nb2O6; SBN) в широкiй областi вимiрювальних умов. Експерименталь-
нi данi були зiбранi з мiкроскопiчного спостереження доменної структури, струмовового перемикання
i реєстрацiї петлi гiстерезису D − E . Петля гiстерезису i дiелектричнi спектри мають сильний зв’язок з
конфiгурацiєю сегнетоелектричних мiкродоменiв. Динамiка доменної структури вивчалася методом не-
матичного рiдкого кристалу (NLC).
Ключовi слова: перемикання поляризацiї, сегнетоелектричний домен, петля гiстерезису, TGS, релаксор,
SBN
31704-6
http://dx.doi.org/10.1007/s00340-005-1989-9
http://dx.doi.org/10.1080/00150193.2011.554269
http://dx.doi.org/10.1007/s100510051071
http://dx.doi.org/10.1007/s10853-005-5954-0
http://dx.doi.org/10.1143/JPSJ.31.506
http://dx.doi.org/10.1080/00150190390206112
http://dx.doi.org/10.1080/00150193.2011.531212
http://dx.doi.org/10.1063/1.1657277
http://dx.doi.org/10.1088/0022-3727/34/14/317
http://dx.doi.org/10.1088/0022-3727/38/23/001
http://dx.doi.org/10.1103/PhysRevLett.99.267602
http://dx.doi.org/10.1007/s10853-005-5915-7
http://dx.doi.org/10.1063/1.3273481
Introduction
Experimental methodology
Results and discussion
Conclusions
|