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The paper presents the results of studies of the structure, piezoelectric and dielectric properties of lead zirconate-titanate ceramics modified with lanthanum of various concentrations (PLZT). It was found that with an increase in the La content, the grain size and the average domain size increase. The PLZT 12/40/60 samples contain both labyrinth-like and periodic domains, as well as different lateral sizes from several hundred nanometers to 3 microns in diameter. It was found that the piezoelectric response signal increases with increasing domain sizes in samples with a high lanthanum content. The fact of the existence of areas on surface of PLZT x/40/60 ceramics having an internal displacement field is established, as evidenced by the asymmetry of the remnant piezoelectric hysteresis loops along the voltage axis. In the samples PLZT 5/40/60 and PLZT 12/40/60, a significant dispersion of the permittivity ε(f) and a maximum of the tangent of the dielectric loss angle were observed in the frequency range from 105 to 106 Hz. This is due to the presence of ionic relaxation polarization, as is the case in ionic dielectrics. It is established that the value of the dielectric constant increases markedly with increasing La, which confirms the occurrence of a rigid unipolar state in the PLZT 12/40/60 ceramic grains. In the samples under study, an increase in the tangent of the dielectric loss angle is observed at low frequencies of the measuring field, which is associated with the contribution of conductivity to tg δ. The dependences of the dielectric loss factor ε” on the dielectric permittivity ε’are constructed. They have the form of Cole-Cole diagrams, which indicates the presence of a relaxation time spectrum, while it was found that the spectrum width in PLZT 5/40/60 samples is about two times less than in PLZT 12/40/60 samples.

The present paper is devoted to the study on the dielectric properties and microstructure of samples of multicomponent ceramics of the PZT system with various Curie temperatures. The coexistence of...

In this article, we study the features of the surface layer formed during mechanical treatment of the sample surface of hard and soft PZT ceramics. We have compared the properties of the surface la...

The dependence of the microstructure and domain structure of sodium niobate ceramics on the production conditions (synthesis temperature of the initial composition and sintering temperature of the ...

In our work, we obtained and studied the samples of porous piezoelectric ceramics based on lithium – sodium niobate (LNN) with a pore content of 10, 20, 30, and 40 volume percent. An analysis of th...

In the present work, we study mixed compounds based on Ca0.28Ba0.72Nb2O6 (CBN28) calcium–barium niobate, and Sr0.61Ba0.39Nb2O6 (SBN61) strontium–barium niobate single crystals. It is shown that electron radiation in an electron microscope (with an accelerating voltage of 15 kV) during the scanning process induces the enhanced DC conductivity of samples along with a drastic rise in the dielectric constant. Furthermore, the dielectric constant as a function of the temperature changes its course, leading to a strong increase in dielectric loss at frequencies below 10 kHz.

This article considers the preparation and investigation of the composite films based on polystyrene with ferroelectric filler. It shows that the permittivity is linearly dependent on the filler concentration. Ferroelectric properties starting appear from the concentration values from 20% to 35%. Due to the polystyrene matrix composite films have high breakdown strength.

Effect of the sintering temperature on the formation of the microstructure, the domain structure, and the ferroelectric properties of a lead zirconate–titanate Pb(Ti x Zr1 – x)O3 piezoelectric ceramics has been studied. It is shown that the ferroelectric phase forms at a sintering temperature of 860°C. At higher sintering temperatures, the main effect on the properties is due to a unit cell deformation and free charge carriers.

The effect of abrasive polishing on the surface topography and domain structure of relaxor and non-relaxor ferroelectric ceramics was studied with the aid of atomic force microscopy (AFM). Two-fold...

The pyroelectric properties of solid state solution single crystals of strontium-barium niobate Sr0.61Ba0.39Nb2O6 (SBN61) and calcium-barium niobate Ca0.28Ba0.72Nb2O6 (CBN28) in a wide temperature range was studied. It is shown that the value in the maximum of the pyroelectric coefficient and its temperature position like the temperature of the ferroelectric phase transition significantly depend on the concentration of CBN28. We obtained that the material CSBN keep the polarized state after cooling down from paraelectric phase if they have been cooled under action of the modulated heat flow.

We have studied the dielectric response dependence on frequency for piezoelectric ceramics based on lead zirconate - titanate (PZT) with three types of electrodes. There are found increase dielectric losses with the decrease of the frequency. Maximum value of tgδ depends on type of electrodes. Also for all samples observed relaxation of dielectric response on low frequency 10−2 – 103 Hz at time. But the total relaxation times are different. This behavior is explained by phenomena on the ceramics – electrode boundary.

The effect of external influences, such as abrasive polishing and application of external field, on the surface charged state of multi-component soft ferroelectric ceramics on the basis of lead-zirconate-titanate was studied.

The microstructure formed during heating of the samples of multilayer actuators obtained by means of thin-film casting is investigated via scanning electron microscopy and atomic force microscopy. It is established that the three main stages of the process are (i) preliminary compaction of the grains with simultaneous decomposition of an organic binder (up to T = 420°C), (ii) powder-particle compaction which is accompanied by an increase in grain size (up to T = 860°C), and (iii) subsequent sintering accompanied by a significant increase in grain size and recrystallization (above T = 860°C).

In this paper, we studied the effect of electroding method on the dielectric properties of PZT ceramics. It was shown that during heat treatment the electrode material is removed from the bulk of ceramics which results in appearance of an additional maximum on the temperature dependence of the dielectric loss at 80°C.

It is shown that magnetron sputtering of PZT on cold substrate with further annealing results in a deficiency of lead. As a result, a structure comprised of pyrochlore matrix with inclusions of perovskite phase nuclei having spontaneous polarization direction at an angle to the film surface in accordance to the piezoresponse force microscopy (PFM) studies is formed.

We have investigated the peculiarities of the formation of the microstructure of lead zirconate-titanate (PZT) ceramics with thickness of 70 and 500 μm with low sintering temperatures after various heat treatments. It has been found that formation of the grain and domain structure depends on the sample thickness and temperature of sintering.

Results from a comparative study of the dielectric properties of paratellurite plates cut perpendicular to the crystallographic directions [010], [1\(\overline 1\) 0], and [001], performed in the temperature range of 23 to 360°C, are presented. It is shown that both the dielectric constant and the type of its dispersion depend on the direction inside the crystal. A model to explain the mechanisms of dispersion is proposed.

In the present work the polarization state of PZT-based ceramics was studied by the thermal square wave method at single frequency. Spatial polarization distributions across the thickness are studied for piezoceramic samples processed with different metallization routes (standard industrial and microwave). It is shown that in the course of natural aging the uniform polarization distribution transforms into a nonuniform one.

Lead ferroniobate ceramics are shown to demonstrate the properties of relaxor ferroelectrics in the low-frequency region. Annealing causes a change in the behavior of the temperature dependences of the complex permittivity. The dispersion diagrams of lead ferroniobate ceramic samples of stoichiometric and nonstoichiometric composition have been compared. The relaxation times have been computed for all the ceramic samples under study.

It is shown that lead ferronyobate Pb2FeNbO6 (PFN) ceramics exhibit ferroelectric relaxor properties at low frequencies. The possible mechanisms of conductivity in PFN ceramics are analyzed.

In the present work the samples of complex oxide compounds on the basis of bismuth titanates with chalcolamprite structure type and layered perovskite doped with Cr, Fe and Co were studied at room temperature by the method of dielectric spectroscopy in the frequency range of 30 to 10 6 Hz.

In the present work the effect of porosity ceramics PZT on the dielectric properties was studied. It is shown that the presence of pores leads to decrease of the real part of the dielectric permittivity in the frequency range of 25 Hz – 1 MHz also as to non-stability of the dielectric characteristics in the phase transition region.