Two-phase dielectric polar structures in 0.1NBT-0.6ST-0.3PT solid solutions

Abstract In this work we address the peculiarities of the macroscopic responses in ternary 0.1Na0·5Bi0·5TiO3-0.6SrTiO3-0.3PbTiO3 (0.1NBT-0.6ST-0.3PT) solid solutions. These solid solutions exhibit a spontaneous first order relaxor to normal ferroelectric phase transition. The phase transition is accompanied by a broad dielectric relaxation which expands over 10 orders of magnitude in frequency just above the phase transition temperature. The temperature dependence of polarization shows that non-zero net polarization persists above the phase transition temperature. Below the phase transition temperature, it is not possible to describe the temperature dependence of polarization with a power l…

Description of Relaxor State in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 System of Solid Solutions

Vogel-Fulcher law, traditionally applied to describe dispersion of dielectric permittivity in relaxor ferroelectrics, requires introduction of two different relaxation mechanisms above and below freezing temperature correspondingly. Extending distribution function of relaxation times, previously known for low-temperature region, allows creating common description of relaxation in all range, where distribution function of relaxation times can be regarded as wide, without freezing at certain temperature.

Influence of Structure Ordering, Defects and External Conditions on Properties of Ferroelectric Perovskites

Results of comprehensive studies of the (A’A“)(B’B”)O3-ferroelectric perovskites are reported. Examined compositions include Pb1-xLax(Zr0.65Ti0.35)1-x/4O3(PLZT), PbSc0.5Nb0.5O3(PSN), PbSc0.5Ta0.5O3(PST), and PMNT, PSNT and PLuNT pseudo-binary systems exhibiting pronounced dielectric, electrooptical, and electromechanical properties. Degree of ordering in the materials has been varied by chemical composition (modification, isomorphic ion substitution), by variation of technology (hot-pressing, specific thermal treatment, thin films), and by irradiation of different kind and intensity (γ-rays, electrons, neutrons).

Interpretation of the Electrocaloric Effect in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3Solid Solutions

Results of direct measurements of electrocaloric effect and polarization are mutually compared in solid solutions 0.4Na1/2Bi1/2TiO3-(0.6-x)SrTiO3-xPbTiO3. Three temperature regions are distinguished in respect of a phase transition temperature. Above the phase transition, electrocaloric effect is determined by orientation of polar nanoregions by electric field. In wide temperature regions above and below the phase transition temperature, the difference between results, obtained from direct electrocaloric effect measurements and from polarization hysteresis loops, is explained by temperature dependence of concentration of polar nanoregions, oriented by electric field. Existence of a common Δ…

Effects of structure ordering, structure defects and external conditions on properties of complex ferroelectric perovskites

Abstract Structural rearrangements in lead-containing (A‘A’) (B’B“)O3 type perovskite compounds are caused by technological treatment, high-energy radiation and ambient conditions. Variation of structure ordering along with modification (substituted or defected solid solutions) may provide promising compositions for applications, e.g., cascade microcryogenic devices (PST solid solutions); efficient piezoelectric materials – here the new (1 – x)Pb(Lu1/2Nb1/2)O3 – xPbTiO3 system in the morphotropic region. The maximum values of the electromechanical coupling coefficients kp = 0·663, kt = 0·481, k 31 = 0·355 were attained in compositions PLuNT 59/41 (Tm = 353°C) near the morphotropic phase bou…

Photoluminescence in Er-doped 0.4Na1/2Bi1/2TiO3-(0.6-x)SrTiO3-xPbTiO3 solid solutions

Photoluminescence and optical second harmonic generation in Er-doped 0.4Na0.5Bi0.5TiO3-(0.6-x)SrTiO3-xPbTiO3 solid solutions is studied. Earlier, it was shown that upon increasing of PbTiO3 concent...

Relation of Dielectric Permittivity and Electric Field Dependence of Polarization in Some Relaxors with Perovskite Structure

The dielectric nonlinearity is studied in ferroelectric relaxors 0.92PbMg1/3 Nb2/3O3-0.08PbTiO3, 0.4Na1/2Bi1/2TiO3-0.5SrTiO3-0.1PbTiO3 and Pb0.9075La0.0925 (Zr0.65Ti0.35)0.9775O3. It is shown that above the temperature of dielectric permittivity maximum nonlinearity of dielectric permittivity corresponds to electric field dependence of polarization. The influence of electric field on distribution of relaxation times is studied below the maximum of dielectric permittivity. The role of internal bias field in Pb0.9075La0.0925(Zr0.65Ti0.35)0.9775O3 ceramics is discussed.

X-ray diffraction and Raman spectroscopy studies in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 solid solutions

The long and short range orders in 0.4Na1/2Bi1/2TiO3-(0.6-x)SrTiO3-xPbTiO3 solid solutions were studied by x-ray diffraction and Raman spectroscopy. X-ray diffraction patterns for these composition...

Dynamics of Phase Transition in 0.4NBT-0.4ST-0.2PT Solid Solution

In this paper we present dielectric spectroscopy results of NBT-(0.6-x)ST-xPT with x = 0.2 solid solution. Dielectric investigations clearly showed a relaxor—normal ferroelectric phase transition at TPT = 419 K and low temperature and low frequency dispersion similar to coexistence of dipolar glass and ferroelectric phase. The mean relaxation time above the phase transition follows Vogel—Fulcher law with following parameters: E A = 0.179 eV, τ 0 = 3.39·10−14 s, T VF = 223 K.

Impact of Thermal Treatment on the Surface of Na0.5Bi0.5TiO3-Based Ceramics

This research was funded by the European Regional Development Fund, grant number 1.1.1.2/VIAA/3/19/558. The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme, grant number 739508.

Grain growth in Na 0.5 Bi 0.5 TiO 3 -based solid solutions

This paper discusses effects of different dopants, sintering technique and parameters on microstructure and properties of pure and Yb, Er-doped Na0.5Bi0.5TiO3 (NBT). All stoichiometric compositions follow the abnormal grain growth mechanism (AGG) and exhibit a bimodal grain size distribution. Bi over-stoichiometry, two step sintering and hot pressing are effective inhibitors of AGG. Microstructure of sintered NBT greatly influences such properties as dielectric permittivity and depolarization temperature.

Phase transitions in modified Na 1/2 Bi 1/2 TiO 3 ‐SrTiO 3 solid solutions

Continuous transfer from relaxor to normal ferroelectric phase transition is found in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 if concentration of PbTiO3 increases. The relaxor properties in NBT solid solutions are described by the power law and Vogel-Fulcher relationship, and concentration dependence of the relevant parameters is discussed. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Phase Transitions in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3Solid Solutions

All sequential steps of transfer from relaxor to normal ferroelectric phase transition are found in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 if concentration of PbTiO3 increases. The relaxor properties in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 solid solutions are described by the power law and Vogel-Fulcher relationship. Concentration dependence of the relevant parameters is discussed. Stability of relaxor and ferroelectric phases is discussed by analyzing behaviour of critical electric fields.

Phase transitions of Pb0.99Nb0.02(Zr0.75Sn0.20Ti0.05)O3ceramics

Abstract The dielectric, elastic and electromechanical properties, electrocaloric effect and thermal expansion of poled and depoled Pb0.99Nb0.02(Zr0.75Sn0.20Ti0.05)O3 samples are presented to evaluate the nature of polar phases existing in the solid solution above room temperature. The Kittel's free energy expansion is used to explain some essential features of physical properties.

DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF 0.8Na0.5 Bi0.5 TiO3-0.2BaTiO3 MODIFIED WITH SODIUM NIOBATE

This work was supported by the Research Council of Lithuania (Project S-LLT-20-4). This work has been supported by Mutual Funds Taiwan–Latvia– Lithuania Cooperation Project Application LV-LT-TW/2020/10.

Dielectric and Polarization Properties of Na0.5Bi0.5TiO3-BaTiO3Solid Solutions with Na and K Niobates

The role of substitution in A- and B-sites of perovskite ABO3 structure in phase transitions is evaluated, comparing (1-y)(0.939Na0.5Bi0.5TiO3-0.061BaTiO3)-yKxNa1-xNbO3 solid solutions with x = 0.0, x = 0.5 and x = 1.0. The influence of deviation from a stoichiometric Na/Bi ratio is also studied. The influence of K0.5Na0.5NbO3, NaNbO3 or KNbO3 reduces mainly to suppressing of ferroelectric properties, like in other perovskite ferroelectrics where Ti is replaced by Nb, and development of the relaxor state. Besides the frequency-dependent dielectric permittivity, the relaxor state in the studied compositions is characterized also by a temperature dependence of critical electric fields, corres…

PHASE TRANSITIONS IN Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 SOLID SOLUTIONS

ABSTRACT Studies of nature of polarization in ternary solid solutions of Na1/2Bi1/2TiO3-SrTiO3-PbTiO3 were done, using measurements of dielectric properties and polarization hysteresis loops. Various stages of relaxor behavior depending on concentration of PbTiO3 were established and compared with other known ferroelectric relaxors.

Phase Transitions in Li, K and Ag Modified Na1/2Bi1/2TiO3-SrTiO3-PbTiO3Solid Solutions

Influence of moderate substitution of Na by monovalent metals Li, K and Ag on structure, phase transitions and dielectric properties of 0.4Na1/2Bi1/2TiO3-0.4SrTiO3-0.2PbTiO3 is studied. Substitution by Li increases, while substitution by K and Ag decreases tetragonality of unit cell. Li increases, Ag decreases while K weakly influences phase transition temperature. The characteristic for the parent phase relaxor state with Tt approaching Tm in case of substitution by K and Li transfers into diffused phase transition without Tm dependence on frequency and extended region of thermal hysteresis.

Relation between deformation and polarization in the region of diffused phase transition of plzt 8/65/35

Abstract The deformation as a function of polarization was measured in PLZT 8-10/65/35 in the region of diffused phase transition. A different behaviour of deformation in the region of double hysteresis loops was observed corresponding to ferroelectric and nonpolar phases as well as to the field induced phase transition region. In the ferroelectric phase the results are described by electrostriction. The decrease of volume as well as small longitudinal deformations at the field induced transition to ferroelectric state are explained by large remanent deformations, existing in the nonpolar phase. Since description of deformation in the framework of electrostriction cannot be motivated in the…

Electrocaloric Effect in (1−x)(0.8Na0.5Bi0.5TiO3-0.2BaTiO3)−xCaTiO3 Solid Solutions at High Electric Fields

This research was funded by the Latvian Science Council Fund, grant number lzp-2020/2-0080. The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme, grant number 739508.

Structure and Dielectric Properties of Na1/2Bi1/2TiO3-BaTiO3Solid Solutions

Dielectric properties, polarization and x-ray diffraction are studied for (1-x)Na1/2Bi1/2TiO3-xBaTiO3 solid solutions in a concentration range above the morphotropic phase boundary. It is showed that all the studied compositions have tetragonal structure with maximal tetragonality slightly above the morphotropic phase boundary. Ferroelectric relaxor behavior is observed in a wide concentration range of BaTiO3. Stability of the relaxor state decreases with increasing BaTiO3 concentration, but only for compositions with low Na1/2Bi1/2TiO3 content the normal ferroelectric-paraelectric phase transition, which is characteristic to pure BaTiO3, occurs. Mechanisms, which influence the change of th…

Phase transitions in Na0.5Bi0.5TiO3-(Sr0.7Bi0.2)TiO3-PbTiO3 solid solutions

ABSTRACTIncreasing of Sr0.7Bi0.2TiO3 concentration in Na0.5Bi0.5TiO3-Sr0.7Bi0.2TiO3 solid solutions causes increasing of Bi/Na relation and vacancies in the A-site of perovskite structure. In temperature dependence of dielectric permittivity, such a change of composition is reflected by transforming of the frequency-dependent shoulder into a maximum characteristic for relaxor ferroelectrics and diminishing of the frequency-independent maximum characteristic for Na0.5Bi0.5TiO3. Here changes in behavior of dielectric permittivity and polarization are studied if PbTiO3 is added in a certain concentration range of Na0.5Bi0.5TiO3-Sr0.7Bi0.2TiO3 solid solutions. Changes of the characteristic temp…

Evolution of dielectric permittivity under applied field in PLZT 8.3/70/30 ceramics

Abstract The jump of dielectric permittivity as function of bias field applied after various duration of storage at the measurement temperature is investigated. The influence of storage time on ϵ(E=) depends on the value of bias field and frequency of measuring field. It is found that ϵ(E=) depends on the path of how particular field value is reached.

The role of structural disorder on luminescence of Eu-doped Na0.5Bi0.5TiO3

A detailed analysis of photoluminescence of Eu-doped Na0.5Bi0.5TiO3 (NBT) is performed using it as a tool for describing the local structure of NBT. The obtained results reveal the low symmetry of the Eu3+ local environment in NBT, as indicated by the observed maximal number of sublevels of the 5D0→7F1 and the 5D0→7F2 luminescence transitions, clearly observed at low temperatures. Approximation of the luminescence spectra by Gaussian peaks provides valuable information about the shift of the involved levels upon change of the excitation wavelength. Variation in the strength of the crystal field in Eu-doped NBT is evaluated. Temperature dependence of the luminescence above room temperature i…

Electromechanical properties of Na 0.5 Bi 0.5 TiO 3 -SrTiO 3 -PbTiO 3 solid solutions

Abstract Thorough studies of electric field-induced strain are presented in 0.4Na1/2Bi1/2TiO3-(0.6-x)SrTiO3-xPbTiO3 (NBT-ST-PT) ternary solid solutions. The increase of concentration of lead x induces crossover from relaxor to ferroelectric. Strain in a relaxor state can be described by electrostrictive behavior. The electrostrictive coefficients correspond to other well-known relaxor ferroelectrics. The concentration region with a stable ferroelectric phase revealed that the polarization dependence of strain does not exhibit nonlinearity, although they are inherent to the electric field dependence of strain. In this case, electric field dependence of strain is described in terms of the Ray…

Influence of sintering temperature on microstructure of Na0.5Bi0.5TiO3 ceramics

Abstract Na0.5Bi0.5TiO3 (NBT)-based compositions are among the most promising lead-free ferroelectrics. Although studies of modification of NBT-based compositions’ properties are a hot topic, there has been very little attention paid to their characterization from the standpoint of ceramics and the process of producing them. Here, we report on comprehensive analysis of the influence of sintering temperature across a wide temperature range (1020–1240 °C) on the complete microstructure and chemical content of NBT ceramics produced by solid state sintering, which is dominating in producing of NBT ceramics. Thorough attention is paid to the grain size distribution, porosity, and inhomogeneity. …

Structure and dielectric properties of Na0.5Bi0.5TiO3-CaTiO3 solid solutions

Despite wide studies of Na0.5Bi0.5TiO3, structure of this material and its connection with the observed physical properties still raise numerous questions due to mutually contradicting results obtained. Here, structure and dielectric properties of poled and unpoled Na0.5Bi0.5TiO3-CaTiO3 solid solutions are studied, projecting the obtained concentration dependence of structure and dielectric properties on pure Na0.5Bi0.5TiO3 as the end member of this material group. X-ray diffraction patterns for Na0.5Bi0.5TiO3-CaTiO3 solid solutions reveal dominating of an orthorhombic Pnma phase, even for the compositions approaching the end composition (Na0.5Bi0.5TiO3), whereas structure of pure Na0.5Bi0.…

Direct and indirect determination of electrocaloric effect in Na0.5Bi0.5TiO3

This work has been supported by the National Research Program in the framework of the project “Multifunctional Materials and composites, photonics and nanotechnology (IMIS2).”

Structure and Physical Properties of Na1/2Bi1/2TiO3-CdTiO3Solid Solutions

Behaviour of ferroelectric properties in Na1/2Bi1/2TiO3-CdTiO3 solid solutions correlates with dependence of lattice symmetry versus concentration of constituents. However, some overlapping is observed in concentration range close to the morphotropic phase boundary. The properties of dielectric permittivity, characteristic for relaxor ferroelectrics, diminish, if concentration of CdTiO3 increases, but it is not influenced by the change of crystallographic symmetry. The electromechanical properties are mostly pronounced in the range of cubic-tetragonal morphotropic phase boundary.

Thermal Expansion, Burns Temperature and Electromechanical Properties in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3Solid Solutions

Thermal expansion and electromechanical properties are studied for compositions Na1/2Bi1/2TiO3-SrTiO3-PbTiO3, belonging to various locations in the phase diagram. The main purpose of the studies is to extend the range of physical properties, which characterise the relaxor state and could be used for comparison with other relaxors. Possibility to evaluate Burns temperature from thermal expansion is discussed. The obtained results are compared to the well-know relaxor ferroelectric PLZT.

Radiation effects in transparent ferroelectric ceramics

Radiation of different types ((gamma) -rays, electrons, neutrons) and fluence has been used to study the defect processes as well as the change of physical parameters in PLZT X/65/35 (X equals 4.5 - 11 at.%) and PbSc 0.5 Nb 0.5 O 3 (PSN) ceramics and to evaluate critical irradiation conditions. Effects on optical (extinction) spectra and dielectric characteristics (polarization, thermal and frequency dependences of dielectric permittivity (epsilon) and losses), dependent on composition and state of phase and polarization have been analyzed by means of annealing in isochronic and prolonged time regimes. A gradual shift of extinction edge to longer wavelengths, reduction of polarization and (…

Study of Tetragonal Phase in 0.4Na1/2Bi1/2TiO3-(0.6-x)SrTiO3-xPbTiO3Solid Solutions by Second-Harmonic Generation

Description of the local symmetry of relaxor ferroelectrics, especially in connection with nature of polar nanoregions, is one of the key questions in research of relaxor ferroelectrics. Unlike such well-known relaxor ferroelectrics as PbMg1/3Nb2/3O3 and (Pb,La)(Zr0.65Ti0.35)O3, ternary solid solutions 0.4Na1/2Bi1/2TiO3-(0.6-x)SrTiO3-xPbTiO3 show clear coexistence of phases of tetragonal and cubic symmetry, which is established by x-ray diffractometry. Since the second-harmonic generation spectroscopy is a sensitive tool in determination of deviation from symmetry, containing a centre of inversion, it is used as an additional method in characterization of structure in 0.4Na1/2Bi1/2TiO3-(0.6…

Structure and dielectric properties at phase transition of Na1/2Bi1/2TiO3-BaTiO3 solid solutions

ABSTRACTPhase coexistence region is studied by x-ray diffraction for Na1/2Bi1/2TiO3-BaTiO3 solid solutions in the tetragonal phase side from the morphotropic phase boundary. The first order ferroelectric phase transition, determined from a jump in the temperature dependence of dielectric permittivity, is located inside the coexistence region of cubic and tetragonal phases and is below the temperature, where tetragonality disappears. At low BaTiO3 concentrations phase transition into ferroelectric state at cooling is slowly approached in time and is smeared over large temperature range. Rietveld method, applied for more precise evaluation of phase content, reveals large local deformations in…

High Electrocaloric Effect in Ferroelectrics

The existing situation in prospects of application of electrocaloric effect (ECE), related to finding ferroelectrics exhibiting high values of ECE, is discussed. Besides 1st order ferroelectric-paraelectric phase transitions, which were most promising till recent time with respect to high values of ECE, there are other approaches, related to ECE in high field range in relaxors and polymers. The restrictions of application of traditional indirect evaluation of ECE in ferroelectrics are discussed.

Phase transitions and properties of perovskite ferroelectric ceramics and films for certain applications

Abstract The structure-properties relationships and phase transitions in perovskite ceramics, and films of PLZT, PLZST, PST, PSN, PMNT compounds are discussed with regard to ordering, relaxor behaviour, pronounced ferroelectric, electromechanical and electrocaloric properties. The theoretical approach is extended to the time dependent Ginsburg-Landau model. The evolution of dielectric properties in relaxors after the change of temperature and electric field creating an increase of dielectric permittivity is found to follow a logarithmic law of decay. A strong electromechanical response is observed in a number of thin films of different compositions.

Dielectric properties of 0.4Na0.5Bi0.5TiO3–(0.6-x)SrTiO3–xPbTiO3 solid solutions

Abstract In this paper we present our measurements of the linear and nonlinear dielectric permittivity of 0.4 Na 0.5 Bi 0.5 TiO 3 – ( 0.6 - x ) SrTiO 3 – xPbTiO 3 solid solutions (x = 0, 0.05, 0.1, 0.15). The dielectric anomaly increases in the system with respect to the concentration of lead, showing that interactions between dipolar entities are modified. The system exhibits dipolar-glass-like behaviour at low values of x ( 0 ⩽ x 0.1 ). Relaxor behaviour emerges in the sample where x = 0.1 . Furthermore, a spontaneous first-order phase transition from relaxor to normal ferroelectric is observed at x ⩾ 0.15 . A few peculiar dispersion regions are observed in the ferroelectric phase, which …

Novel octahedral tilt system a + b + c + in (1 − x)Na0.5Bi0.5TiO3–xCdTiO3 solid solutions

This work has been supported by National Research Program in the framework of project “Multifunctional Materials and composites, photonics and nanotechnology (IMIS2)”.

Electrocaloric Effect in Na1/2Bi1/2TiO3-SrTiO3-PbTiO3Solid Solutions

Electrocaloric effect is studied in a group of triple solid solutions 0.4Na1/2Bi1/2TiO3-(0.6-y)SrTiO3-yPbTiO3. Contribution of electric field-induced phase transition in the total value of temperature change, caused by electric field, is evaluated. The highest value of electrocaloric effect is observed for composition 0.4Na1/2Bi1/2TiO3-0.4SrTiO3-0.2PbTiO3, in which the depolarization temperature, characteristic for relaxor ferroelectrics, merges with the temperature of maximum of dielectric permittivity. Applicability of thermodynamic description is discussed.

The role of disorder on Er3+ luminescence in Na1/2Bi1/2TiO3

Abstract Photoluminescence in Er-doped NBT is studied at different temperatures. Remarkable reduction of the luminescence intensity in the green spectral range is found in the poled state comparing with the depoled state. Luminescence spectra at low temperatures reveal continuous wavelength shift of some maxima belonging to the 4 S 3/2  →  4 I 15/2 transition depending on the excitation wavelength, which is explained by large variety of different environments around Er 3+ related to the random distribution of Na + and Bi 3+ in A-sublattice of the ABO 3 perovskite structure. Poling extends the wavelength range where shift of luminescence maxima is observed in the direction of longer excitati…

Evolution of dielectric properties in transparent PLZT 8.3/70/30 ceramics at the diffused phase transition

Abstract The time evolution of dielectric properties after a temporary change of temperature and electric field is investigated. It is found, that below the temperature of ˛' maximum Tm the change of temperature and electric field creates an increase of dielectric permittivity followed by logarithmic decay when the change of these parameters is finished. At every temperature the dielectric properties are characterized by a unique ˛'(t) independent on previous thermal history. If the applied electric field is E< Ec, the state of polarization is not affected. The dependence on dielectric constant of storage time under field as well as field intensity is determined.

Structure and dielectric properties of Na&lt;inf&gt;1/2&lt;/inf&gt;Bi&lt;inf&gt;1/2&lt;/inf&gt;TiO&lt;inf&gt;3&lt;/inf&gt;-BaTiO&lt;inf&gt;3&lt;/inf&gt; solid solutions

Dielectric properties, polarization and x-ray diffraction are studied for (1−x)Na 1/2 Bi 1/2 TiO 3 -xBaTiO 3 solid solutions in a concentration range above the morphotropic phase boundary. It is showed that all the studied compositions have tetragonal structure with maximal tetragonality slightly above the morphotropic phase boundary. Ferroelectric relaxor behavior is observed in a wide concentration range of BaTiO 3 . Stability of the relaxor state decreases with increasing BaTiO 3 concentration, but only for compositions with low Na 1/2 Bi 1/2 TiO 3 content the normal ferroelectric-paraelectric phase transition, which is characteristic to pure BaTiO 3 , occurs. Mechanisms, which influence…

Dielectric polarization in PLZT X/65/35 and PbMg1/3Nb2/3O3at the diffuse phase transition

Abstract The transformation of the hysteresis loops in PLZT x/65/35 in the region of diffuse phase transition is discussed in relation to the behaviour of dielectric permittivity. The Vogel-Fulcher type dielectric relaxation is used to describe the discussed phenomena.

Phase State and Structure of Ferroelectric Ceramics under Irradiation

Phase Transitions and Electrocaloric Effect in Ca-Modified Na1/2Bi1/2TiO3–SrTiO3–PbTiO3Solid Solutions

Revision of the freezing concept in relaxor ferroelectrics: the case of Na0.5Bi0.5TiO3-Sr0.7Bi0.2TiO3 solid solutions

Presence of a frequency-independent maximum and a frequency-dependent shoulder in temperature-frequency dependence of dielectric permittivity are characteristic features of NBT-based solid solution...

Thermodynamic properties at the phase transition of Pb(Zr, Sn, Ti)O3solid solutions

Abstract Field induced deformation and electrocaloric effect are investigated in the vicinity of phase transition at 163°C. The sharp increase of electrostriction below Tc is explained by the field induced ferroelectric to antiferroelectric phase transition. The antiferroelectric phase appears and remains stable below Tc in the absence of field. Elastic compliance and thermal expansion as functions of temperature are studied.