Stanislav Aleksandrovich Gridnev

• Doctor of physical-mathematic sciences
• Professor (Full) at Voronezh State Technical University

The low-frequency internal friction Q–1 and shear modulus G have been studied by the inverted torsion pendulum method for a series of crystals belonging to potassium dihydrogen phosphate family: KH2PO4, KD2PO4, 0.95KH2PO4–0.05NH4H2PO4, RbH2PO4, RbH2AsO4, and CsH2AsO4. A number of anomalies have been revealed in the temperature dependences Q–1(T) an...

The monograph presents mathematical methods and a set of mathematical models describing, within the framework of phenomenological theory, phase transitions in 0D-. 1D-, 2D-, 3D-dimensional ferroelectrics, ferroelastics, ferromagnets and their static and dynamic physical properties near the phase transition point. The influence of the parameters cha...

Temperature dependences of the real and imaginary parts of the dielectric permittivity in the ferroelectric Ba1-xSrxTiO3 solid solution are investigated at a frequency of 1 kHz. It was found that an increase in the strontium concentration leads to a shift in the temperature of the dielectric permittivity maximum towards lower temperatures and the d...

The internal friction spectra of an amorphous thin-film bismuth ferrite deposited on a silicon substrate were studied. The temperature dependence of mechanical losses near the glass transition temperature revealed a wide maximum of internal friction associated with α-relaxation of the amorphous structure. In this temperature region, two linear sect...

High-temperature internal friction in an amorphous CuTi alloy is investigated. Exponential regions with different activation energies are observed on the dependence of internal friction on temperature on both sides of the glass transition temperature. An exponential increase in the background of internal friction with temperature in both sites is a...

The temperature dependences of internal friction and Young’s modulus in ferroelectric Ba0.8Sr0.2TiO3 ceramics under bending oscillations were investigated at frequencies of the several hertz. The effect of the heating rate and the frequency of oscillations on the internal friction peak height near the Curie temperature was studied. The fluctuation...

The temperature and amplitude dependences of internal friction Q⁻¹ and shear modulus G for the Na0.875Li0.125NbO3 solid solution were studied in the temperature range of 300–700 K. It was found that the material undergoes two structural phase transitions near temperatures T1 ≈ 620 K and T2 ≈ 559 K. Both low-temperature phases are ferroelectric one,...

The methods of preparation, as well as the structure and most relevant physical properties of amorphous materials based on ferroelectrics with perovskite structure are reviewed. The theoretical basis for the possibility of ferroelectricity in non-crystalline solids is discussed. The structural relaxation in a glassy state and the crystallization pr...

Samples of piezoactive composition 0.89PbMg0.33Nb0.66O3 (MZF)−0.11PbZr0.48Ti0.52O3 (PMN–PZT) by two-stage ceramic technology were obtained. The values of the effective piezomodule d31 = (600–1400) pC/N for the resulting material significantly exceed the values of d31 = 150 pC/N for the commercially available family of lead zirconate – titanate cera...

The temperature dependences of the dielectric permittivity and dielectric loss tangent in the ferroelectric ceramic Ba0.8Sr0.2TiO3 have been studied at frequencies from 25 Hz to 120 Hz. It was found that the phase transition at the Curie point (ТС ≈ 338 K) is diffused in the temperature range of ∼ 30 K. The temperature dependence of the local order...

The features of the frequency dependence of conductivity and the current-voltage characteristics in magnetoelectric composite ceramics 0.85BiFeO3–0.15MgFe2O4 in the temperature range (300–500) K and frequencies (10–500) kHz are studied.

A new Aurivillius Bi5Ti3Fe0.5Ni0.5O15 compound was prepared using the conventional ceramic technology. The features of the temperature dependences of the dielectric constant ε′ and the dielectric loss tgδ were studied in the temperature range from 300 to 750 K. These dependences indicate a significant conductivity contribution to the ε′ and tgδ as...

The electrical conductivity of the particulate magnetoelectric composite (x)Mn0.4Zn0.6Fe2O4 − (1 − x)PbZr0.53Ti0.47O3 with x = 0, 0.1, 0.2, 0.3, and 0.4 at frequencies from 2 to 50 kHz over a temperature interval of 290 − 670 K is studied. It is revealed that below the ferroelectric Curie point, the composite conductivity is frequency-dependent and...

In the temperature range from –180 to +50 °C, at frequencies of the order of several hertz, the internal friction Q⁻¹ and the shear modulus G in CoO crystals, nominally pure and with Ni additives, were studied. The temperature dependence of internal friction has a complex form. A Q⁻¹ maximum was found near ∼160 °C, which has a dislocation nature, a...

The temperature dependences of the internal friction Q⁻¹ and the Young’s modulus E for ferroelectric ceramics Ba0.8Sr0.2TiO3 both without dopant and doped with La were measured at hertz frequencies. A decrease in the Q⁻¹ maximum and an increase in E value compared with the initial undoped sample are observed in the La-doped sample near the phase tr...

Elastic (elastic compliance) and anelastic (internal friction) properties of a particulate magnetoelectric composite (x)Mn0.4Zn0.6Fe2O4–(1 − x)PbZr0.53Ti0.47O3 (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.6) at a frequency of ≈30 Hz over a temperature range from 290 to 700 K are studied. Temperature dependences of elastic compliance and internal friction near...

The dielectric and magnetic properties of mixed magnetoelectric (x)Mn0.4Zn0.6Fe2O4–(1 – x) · PbZr0.53Ti0.47O3 (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.8) composites have been studied in the temperature range near the ferroelectric and magnetic phase transitions. The influence of the composite compositions on the thermodynamic parameters of the initial pha...

The internal friction in particulate ceramic composites of (x)Mn0.4Zn0.6Fe2O4 –(1-x)PbZr0.53Ti0.47O3 (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.6) in the vicinity of the phase transition temperatures was studied. We observed the influence of the composite composition on the exponent that characterizes a temperature dependence of the internal friction near t...

A two-stage ceramic technology was used for producing a family of (1-x) BiFeO3 - x MgFe2O4 heterophase systems. The study of the magnetic hysteresis loop revealed the presence of a ferrimagnetic response. The experimentally obtained concentration and temperature dependences of the magnetic permeability made it possible to consider the influence of...

Direct magnetoelectric (ME) effect in two-layered Tb0.12Dy0.2Fe0.68/Epoxy − PbZr0.53Ti0.47O3 composites containing magnetostrictive layers of the epoxy with distributed in it Tb0.12Dy0.2Fe0.68 granules and piezoelectric layers of the PbZr0.53Ti0.47O3 ceramics was studied. It was found, that the gradient distribution of Tb0.12Dy0.2Fe0.68 granules in...

Sr₍₂₊ₓ₎Bi₍₄₋ₓ₎Ti₍₅₋ₓ₎NbₓO₁₈ materials with x = 0.2, 0.4, 0.6, 0.8, and 1 are synthesized. Investigations of the dielectric constant of the samples reveal an increase in the blurring of the phase transition as the share of titanium ions substituted for niobium ions grows. The Burns temperature and the temperature corresponding to the dielectric perm...

Temperature dependences of the dielectric losses in (x)Mn0.4Zn0.6Fe2O4–(1–x)PbZr0.53Ti0.47O3 magnetoelectric composites are studied at frequencies of 200 to 5000 Hz near the ferroelectric phase transition. A relaxation peak of the dielectric losses is revealed that, according to experiments, is mainly due to the mechanism of a new phase emerging in...

Dielectric properties of 0.85BiFeO3–0.15MgFe2O4 composite fabricated with conventional ceramic technology are studied in the temperature interval of 20–250°C at frequencies of 25 Hz to 1 MHz. Dielectric relaxation is observed, the nature of which is discussed in the context of a mechanism of interaction between ferroelectric domain boundaries and p...

The inverse magnetoelectric effect and internal friction in two-layer composites based on ferromagnetic Tb0.12Dy0.2Fe0.68 and piezoelectric PbZr0.53Ti0.47O3 are studied in an ac electrical field in the frequency range of 52–213 kHz at temperatures of 293 to 400 K. A correlation is found between the internal friction and the efficiency of the invers...

Resistivity study of two-phase ceramics (1-x) BiFeO3 - x MgFe2O4 showed the presence of PTC thermistor anomaly at a temperature of 260°C, which is less than the phase transition temperatures in the starting components of the system. To elucidate the nature of the thermistor anomaly, the measurements of samples annealed in reducing H2 or CO2 atmosph...

Particulate magnetoelectric composites (x)Mn0.4Zn0.6Fe2O4 – (1-x)PbZr0.53Ti0.47O3 with x = 0, 0.1, 0.2, 0.3, 0.4, and 0.8 have been prepared using the ceramic technology. Prepared composites with x = 0.2 was revealed to be characterized by the crossover from the ordinary ferroelectric state to the relaxor ferroelectric state, and figure of merits o...

The dependences of the dielectric loss tgδ on amplitude of the electric field E∼ in multidomain triglycine sulfate single crystal below the phase transition temperature were studied. It was found that in weak fields the rapid growth of tgδ with field E∼ occurs, then the dependence tgδ(E∼) passes the peak, and then decreases. The results discussed i...

Nanocomposite thin films containing Pb(Zr0.53Ti0.47)O3 (PZT) and Co or Ni are deposited on pyroceramic and silicon substrates by ion-beam sputtering. Structural characterizations show that only PZT and Co or Ni phases exist in the composite films, and the crystalline Co or Ni nanogranules with average sizes of 3.0–8.0 nm are randomly embedded in th...

The internal friction in mixed magnetoelectric composites xMn0.4Zn0.6Fe2O4–(1‒x) PbZr0.53Ti0.47O3 (x = 0.1, 0.2, 0.4) prepared by the ceramic technology has been studied near the ferroelectric phase transition temperature at a frequency of 30 Hz. The contributions to the internal friction due to the kinetics of the phase transition and due to the i...

The studies of the dielectric properties of the obtained samples revealed the frequency dispersion and significant smearing of the peak of the real part of the permittivity and the dielectric loss tangent, which indicates the relaxor behavior of the material Sr₂.₈Bi₃.₂Ti₄.₂Nb₀.₈O₁₈, which is not characteristic of pure Sr₂Bi₄Ti₅O₁₈ (without substitu...

The purpose of this research is the synthesis of new layered ferroelectrics, with the general formula Sr₍₂₊ₓ₎Bi₍₄₋ₓ₎Ti₍₅₋ₓ₎NbₓO₁₈ where 0 ≤ x ≤ 1 with the structure of Aurivillius Phases (AP), and the establishment of regularities of the influence of the chemical composition and the degree of structural disorder on the physical properties of these...

Investigation of the influence of substitution of titanium cations Ti⁴⁺ for niobium cations Nb⁵⁺ on the occurrence of relaxor properties of layered perovskite with the structure of Aurivillius phases Sr₍₂₊ₓ₎Bi₍₄₋ₓ₎Ti₍₅₋ₓ₎NbₓO₁₈, as well as the smearing of the phase transition in this material. The study was carried out for 0 ≤ x ≤ 1 with a step of...

Thin-film nanogranular metal–dielectric composites (x)Ni–(1−x)[Pb0.81Sr0.04(Na0.5Bi0.5)0.15][(Zr0.575Ti0.425)]O3 (denoted as (x)Ni–(1−x)PNBZT) were prepared by the ion-beam sputtering method. The X-ray diffraction analysis has revealed the presence of two phases in the composites: a crystalline Ni phase and an amorphous PNBZT phase. Composites (x)N...

Samples of three-layer amorphous ferromagnet-piezoelectric-amorphous ferromagnet composites with different thicknesses of the Fe0.45Co0.45Zr0.1 layers have been fabricated by ion-beam sputtering of the Fe0.45Co0.45Zr0.1 cast alloy on largest surfaces of the PbZr0.53Ti0.47O3 piezoelectric plates prepared by ceramic technology. The influence of the a...

According to the standard ceramic technology obtained solid solution (x)BiLi₀.₅Sb₀.₅O₃ — (1−x)Na½Bi½TiO₃. In the temperature range from 23 to 500 °C studied the temperature dependence of the real part of permittivity ε' and tan(δ) at frequencies of 1 to 1,000 kHz in a weak measuring field of about 10 V/cm, which bind to the presence in these sample...

The direct magnetoelectric effect has been studied in samples of two-layer composites containing 8 × 6 × 0.3-mm layers of the piezoelectric material PbZr0.53Ti0.47O3 and 6 × 6 × A-mm layers (A = 0.3, 0.6, 0.9, 1.2, and 1.5) of the ferromagnet Tb0.12Dy0.2Fe0.68 and epoxy adhesive in the frequency range of 10–253 kHz at room temperature. It has been...

The two-layered Tb0.12Dy0.2Fe0.68-PbZr0.53Ti0.47O3 magnetoelectric composites have been prepared by the deposition of ferromagnetic layers of different thicknesses from a thoroughly mixed Tb0.12Dy0.2Fe0.68 ferromagnetic powder and an epoxy glue on preliminarily polarized PbZr0.53Ti0.47O3 piezoelectric layers. The dependences of the inverse magnetoe...

The structural, magnetic, and vibrational properties of PbFe0.5Nb0.5O3 relaxor multiferroic have been studied by means of x-ray, neutron powder diffraction, and Raman spectroscopy at pressures up to 30 GPa. Two successive structural phase transitions from the initial R3m polar phase to Cm and Pm monoclinic polar phases were observed at P = 5.5 and...

The internal friction and shear modulus for the particulate magnetoelectric composite (x)PbZr0.53Ti0.47O3–(1 − x) Mn0.4Zn0.6Fe2O4 have been studied over a temperature range from room temperature to 670 K. In the vicinity of the ferroelectric phase transition temperature, we have observed the internal friction peak that is explained in terms of the...

The features of low-frequency dielectric losses in the improper ferroelectric crystal of terbium molybdate Tb2(MoO4)3 were investigated in the vicinity of the Curie point. To explain the relations observed, the attenuation mechanism of low frequency electrical oscillations at first order phase transitions was used, which based on the concept of a d...

At frequencies of the measuring magnetic field of 9.9–253 kHz over a temperature range from 79 K to 289 K the magnetoelectric effect in two-layered ferromagnetic-piezoelectric composites Tb0.12Dy0.2Fe0.68 – PbZr0.53Ti0.47O3 with ferromagnetic Tb0.12Dy0.2Fe0.68 and piezoelectric PbZr0.53Ti0.47O3 layers of 6 × 6 × А mm3 (A = 0.6, 0.9, and 1.2) and 8...

We have studied the magnetodieletric response of polycrystalline samples of the perovskite relaxor ferroelectric Pb(In0.5Nb0.5)O3. Dielectric anomalies of ′ and ′ are clearly observed at the phase transition from ferroelectric rhombohedral phase to rhombic antiferroelectric phase (TC = 36°C) and then at the phase transition from antiferroelectric p...

A family of new lead-free materials with the general formula BiMe 2/3Sb1/3O3 (Me = Mg, Ni, Co, Zn) have been synthesized using the standard ceramic technology. The temperature dependences of the permittivity ɛ′ have been studied at frequencies from 0.5 to 1000 kHz in the temperature range from 300 to 800 K. At high temperatures, the permittivity ɛ′...

The temperature dependences of the complex permittivity of ferroelectric PbFe1/2Nb1/2O3 have been studied at frequencies of 25, 500, and 104 Hz. It has been found that the phase transition is smeared in the temperature range ∼90 K. In the smearing region, there is a deviation from the Curie-Weiss law, which begins to be obeyed only above the Burns...

Electronic properties of thin-film granulated nanocomposites Co x (LiNbO 3 ) 100−x , where x = 12–83 at.%, have been studied. The analysis of temperature dependences of a conductivity for compositions having Co content lower than the percolation threshold x = 58 at. % has revealed that in the low temperature region (80–190 K) a Mott's type variable...

System of solid solutions PbMg1/3Nb2/3O3—PbZr0.53Ti0.47O3 (PMN-PZT) has been investigated in order to establish the relation between the dielectric parameters, electrostrictive properties and the volumes of critical nuclei, which appear at the diffuse phase transition. Polar region sizes were estimated using two different methods.

The pyroelectric response is measured using the dynamic method in preliminarily polarized magnetoelectric 0.8PbZr0.53Ti0.47O3-0.2Mn0.4Zn0.6Fe2O4(0.8 PZT-0.2 MZF) and 0.8PbZr0.53Ti0.47O3-Ni0.4Zn0.6Fe2O4 (0.8 PZT-0.2 NZF) composites, where PZT is a ferroelectric, and MZF and NZF are manganese-zinc and nickel-zinc ferrites, respectively. Values of the...

The low-frequency process of dielectric relaxation in the new lead-free compound BiLi0.6W0.4O3 prepared by conventional ceramic technology is studied. The features of dielectric relaxation are discussed in terms of a model of interaction between the domain boundaries and point defects of a crystalline lattice.

The dispersion of complex permittivity in ferroelectric PbFe1/2Nb1/2O3 with diffused phase transition at frequencies of 20 Hz-10 kHz was studied. Dielectric measurements revealed that polarization 1/f noise occurs in the region of coexistence of polar and nonpolar phases. It was found that the temperature dependence of parameter α exhibits a singul...

The internal friction (Q−1) in KH2PO4, RbH2PO4, and RbH2AsO4 crystals is investigated using the torsion pendulum technique at frequencies of some Hz in the temperature range from −240°C to the crystal decomposition temperature. The low frequency mechanism of the Q−1 in the vicinity of the Curie point for the crystals under study is considered in de...

The features of infrasonic frequency (10-3-10-1 Hz) internal friction, Q-1, and shear modulus, G, in different ferroelectric and ferroelastic crystals have been studied using the inverse torsion pendulum technique over a wide temperature range and different external fields which lead to the change of a real crystal structure. It is shown that the a...

The dielectric permittivity and polarization measurements have been performed in mixed crystals K1-x(NH4)xH2PO4 (KADP-x%) with x = 0.19, 0.24, and 0.32. It was found out that the ferroelectric phase transition in KADP-19 is preceded by a mixed ferroelectric-paraelectric state. The coexistence of ferroelectric and proton-glass states in KADP-24 take...

Internal friction Q −1 was studied in nominally pure and Li-doped CoO crystals at frequencies of about a few Hz in the temperature range from −180 to 20°C. Doping Co crystals with Li results in a new relaxation maximum of Q −1 at −115°C at a frequency of 3 Hz. The occurrence of this maximum is related to the reorientation of the Co3+-Li1+ elastic d...

The dc conductivity and kinetics of isothermal crystallization of amorphous nano-composites Co x [Pb0.81Sr0.04(Na0.5Bi0.5)0,15(Zr0.575Ti0.425)O3]100− x with different compositions at a presence of an alternating electric field have been studied. It is revealed that the crystallization rate increases as strength of electric field is increased becaus...

The magnetoelectric effect in two- and three-layered composites based on nickel-zinc ferrite and lead zirconate-titanate was investigated. The value of the magnetoelectric response in layered composites depends largely on the frequency of the alternating magnetic field, the volume ratio of the electric phase forming the composite, and the mechanica...

The properties of the new lead-free compound BiLi0.6W0.4O3, obtained using ceramic technology, were studied by dielectric and mechanical spectroscopy. The anomalies of internal friction are, along with the elastic and dielectric properties observed experimentally at a temperature of 350°C, related to its structural phase transition. Dielectric and...

A crystallization process of amorphous samples of PbTiO3 has been studied during 8 hours isothermal annealing at various temperatures in a vicinity of crystallization temperature Tcr = 600°C. It was revealed, that transition of amorphous material to a crystalline state is accompanied by a growth in value of its conductivity during the all time of i...

Temperature dependences of internal friction Q−1 in Pb(Fe0.5Nb0.5)O3 ferroelectric ceramics at various heating rates is measured and mechanism of Q−1 at the phase transition in the Curie point is discussed. Amplitude dependences of Q−1 in Pb(Fe0.5Nb0.5)O3 is studied. It is shown that the main contribution to nonlinear mechanical losses both in the...

The effect of d.c. electric field on a temperature dependence of dielectric permittivity of 0.925NaNbO3-0.075(PbxBa1−x)SnO3 solid solutions was investigated. The dependencies of Δϵ(T) = ϵ(E=) − ϵ(E= = 0), where E= is the d.c. field, were obtained. For compositions with the concentration x = 0 and x = 1 the appearance of ferroelectric and antiferroe...

A shift of ferroelectric (TC) and magnetic (TN) phase transitions in the (x)PbZr0.53Ti0.47O3–(1 − x)Mn0.4Zn0.6Fe2O4 (PZT–MZF) particulate ceramic composite depending on a volume ratio of the MZF ferrite and the PZT ferroelectric, respectively, has been studied. It is established that one reason for the TC and TN shifts is a mutual doping of the fer...

Lead-free BiMe2/3Sb1/3O3 (Me = Co, Mg, Ni, Zn) ceramic compounds have been successfully synthesized by the conventional method. X-ray diffraction technique was used to investigate the phase evolution of calcined powders and sintered samples. Microstructures of sintered pellets were studied by the scanning electron microscopic techniques. To reveal...

Physical properties of new ferroic BiLi0.5Sb0.5O3 ceramic material have been studied by dielectric, mechanical, and thermal spectroscopy methods. The experimental data revealed two structural phase transitions in BiLi0.5Sb0.5O3 ceramics near 50 and 220°C.

Magnetic and magnetoelectric properties of particulate (x)PbZr0.53Ti0.47O3–(1−x) Mn0.4Zn0.6Fe2O4 composites, where x is 0; 0.2; 0.4; 0.6; 0.8; and 1.0, have been studied. Measurements of magnetization—magnetic field loops, temperature and field dependences of the differential magnetic susceptibility as well as the transverse magnetoelectric voltage...

The inverse magnetoelectric effect in two-layer composite consisting of piezoelectric PbZr0.53Ti0.47O3 (PZT) and ferrite Mn0.4Zn0.6Fe2O4 (MZF) plates has been studied. Dependences of the magnetic induction variation Bm on amplitude and frequency of ac electric field as well as on magnetic field strength, temperature, and composite composition for l...

The magnetoelectric effect in two- and three-layered composites based on nickel-zinc ferrite and lead zirconate-titanate was investigated. The value of the magnetoelectric response in layered composites depends largely on the frequency of the alternating magnetic field, the volume ratio of the electric phase forming the composite, and the mechanica...

The magnetodielectric (MD) effect in two-layer composites consisting of polarized PbZr0.53Ti0.47O3 (PZT) ceramics and Mn0.4Zn0.6Fe2O4 (MZF) ferrite plates has been studied. The MD coefficient Δϵ/ϵ(0) was established to depend on a thickness of the magnetostriction layer, a bias magnetic field strength, and an electric field frequency. Using thermod...

Dielectric properties of new lead-free BiLi0.5Sb0.5O3 ceramics in a wide temperature range and at frequencies from 25 Hz up to 50 kHz have been studied. Dielectric ϵ′ and tgδ anomalies, observed at temperatures 323, 473 and 830 K, are related to structural phase transitions. The dispersion behavior of the dielectric constants in high temperature re...

The magnetoelectric (ME) effect in two- and three-layered composites made up of polarized ceramic plates of lead zirconate-titanate PbZr0.53Ti0.47O3 (PZT) and manganese-zinc ferrite Mn0.4Zn0.6Fe2O4 (MZF) has been studied. Dependences of the transverse ME voltage coefficient (α31) on the magnetostrictive layer thickness and the magnetic field intens...

The magnetoelectric composites xNi0.4Zn0.6Fe2O4-(1 - x)Pb0.95Sr0.05Zr0.53Ti0.47O3 ( x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by ceramic technology. It is established that these composites have a two-phase structure. The magnetic and ferroelectric properties of the composites were studied by measuring the hysteresis loops and the temperature de...

The elastic, inelastic, and dielectric properties of the magnetoelectric composite xPbZr0.53Ti0.47O3-(1 − x)Mn0.4Zn0.6Fe2O4 (PZT-MZF) are studied in the temperature range from room temperature to 673 K. The influence of the ferroelectric PZT phase on the magnetic phase transition and the magnetic MZF phase on the ferroelectric phase transition is r...

The dielectric properties of relaxor ferroelectric ceramics (1 – x)PbMg1/3Nb2/3O3–(x)PbZr0.53Ti0.47O3(PMN–PZT) have been studied at various frequencies in the temperature range of the diffuse phase transition. Dispersion of the complex dielectric permittivity ε * characteristic for relaxors was revealed in the vicinity of the ε * maximum temperatur...

Using an inverted torsion pendulum, the peculiarities of low-frequency shear elastic and anelastic properties of the ferroelastic crystals Ba 2 NaNb 5 O 15 and K 2 Ba(NO 2 ) 4 have been investigated for various crystallographic oriented samples at temperature variation in the vicinity of their phase transition points. The work gives insight into th...

The features of acoustic property investigations carried out in different classes of ferroelastic crystals are considered. The special attention is given to elastic and anelastic properties of ferroelastics at low frequencies: the nonlinear hysteretic dependence of a strain on an external mechanical stress, a mechanical relaxation, a spontaneous tw...

The system of solid solutions (1-x)PbMg1/3Nb2/3O3-xPbZr0.53Ti0.47O3 (PMN-PZT) was investigated. On the base of the experimental study of dielectric spectroscopy, dielectric nonlinearity under external bias field up to 15 kV/cm, and differential thermal analysis the crossover from relaxor to ordinary ferroelectric state has been revealed. Criteria a...

Conductivity of thin-film heterogeneous Cox(PZT)1 − x structures has been studied in a wide ranges of metallic phase concentrations and temperatures. The crystallization kinetics of amorphous samples of Cox(PZT)100 − x nanocomposites has been investigated by analyzing the time dependences of their conductivity. The main parameters of the crystalli...

The dielectric properties of relaxor ferroelectric ceramics (1 − x)PbMg1/3Nb2/3O3-(x)PbZr0.53Ti0.47O3 (PMN-PZT) have been studied at frequencies from 40 Hz to 1 MHz in the temperature range of the diffuse phase transition. It is established that the dielectric relaxation generates 1/f noise, whose spectral density depends on the relaxor composition...

Using a torsion pendulum, the peculiarities of low-frequency shear elastic and anelastic properties of the improper ferroelastic crystal K2Ba(NO2)4 have been investigated for various crystallographic oriented samples at a temperature range in the vicinity of the phase transition point (TC = 420 K). The work gives insights into the nature of the int...

The dielectric constant of amorphous Bi1.8Pb0.3Sr2Ca2Cu3−x KxOx (x = 0.2–0.3) is measured as a function of the static electric field strength. It is found that, as the field strength increases, the dielectric constant decreases following a quadratic law. This behavior of the dielectric constant in a static electric field indicates nonlinear dielect...

The electrical and dielectric properties of thin-film heterogeneous nanostructures of Cox(LiNbO3)100 − x were studied in a wide concentration range of the metallic phase at room temperature. The percolation threshold characteristic of granular metal-dielectric systems was found. At low concentrations of the metallic phase, the concentration depende...

The dependence of the dielectric permittivity on the strength of a dc electric field in the glassy dielectric material Bi1.8Pb0.3Sr2Ca2Cu2.7K0.3Oz was studied. It was revealed that the value of the dielectric constant is decreased by a quadratic law as the dc field strength is increased. Such behavior of the dielectric permittivity under external b...

The electrical and dielectric properties of nanoheterogeneous Co - LiNbO3 thin-film structures were studied in a wide range of concentrations of the metallic phase at room temperature. The frequency dependence of the conductivity was investigated, which, according to the Mott model, corresponds to the hopping conduction mechanism. It was found that...

The T–x phase diagram of (1 − x) [0.7PbZrO3–0.3(K0.5Bi0.5)TiO3]– xSrTiO3 (x = 0–0.7) solid solutions has been plotted using data from x-ray and dielectric studies. It was found that compounds with x < 0.25 and 0.25 < x ≤ 0.70 undergo diffuse phase transitions to ferroelectric rhombohedral and tetragonal phases, respectively. The diffuseness of phas...

The temperature dependence of the local order parameter and relaxation time distribution function have been determined in (1 – x)PMN–xPZT ceramic samples via dielectric permittivity. Above the Burns temperature, the permittivity was found to follow the Currie–Weiss law, and with temperature decreasing the deviation was observed to increase. A local...

Spontaneous twisting of (NH4)2SO4 crystals at the phase transition from the paraelectric phase Pnam to the ferroelectric phase Pna2 (T C = 223 K) was studied using the method of low-frequency torsion pendulum. It is shown that the macroscopic twisting of samples is caused by the rearrangement of ferroelastic twins with the {011} and {031} twinning...

The dielectric properties of PbTiO3, PbFe1/2Nb1/2O3 and PbMg1/3Nb2/3O3 in amorphous and crystallized states have been studied within a temperature range of 20–750 °C. The anomalies of dielectric permittivity ϵ and dielectric losses tgδ caused by crystallization process as well as processes in electron subsystem were revealed. The nature of these an...

The dielectric behaviors of (1−x)Pb(Mg1/3Nb2/3)O3−xPb(Zr0.53Ti0.47)O3 (PMN-PZT) relaxor ferroelectric ceramics of several compositions (x = 0.05–0.30) have been studied under high bias electric field. The dielectric constant decay with dc electric field was observed in the range of diffuse phase transitions. The nonlinear dielectric response was co...

The dielectric properties of PbMg1/3Nb2/3O3 in amorphous and crystallized states have been studied within a temperature range of 80–920 K. The maximum of dielectric losses for amorphous state was found below the temperature corresponding to the relaxor transition in crystalline lead magnesium niobate (Tm ≅ 270 K). At high temperatures two anomalies...

The DC and AC conductivities and dielectric properties of PbTiO3 in amorphous and crystallized states have been studied within a temperature range of 20–680°C. The anomaly in the ϵ′(T) dependence for amorphous state was found in the vicinity of a temperature corresponding to ferroelectric transition of crystalline lead titanate (TC ≅ 500°C). The an...

The analysis of dielectric and polarization properties of mixed ferroantiferroelectric crystals (1 −x )KDP-xADP and related systems has been performed for broad range of concentration x. The problems concerning the composition effect on spontaneous polarization, diffuseness of phase transitions, dynamics of proton glass transition and phase coexist...