An analysis of heterophase states was carried out for ferro-active solid solutions of the system(1-x-y)NaNbO_(3)-x KNbO_(3)-y CdNb_(2)O_(6).A complete stress relief at interfaces between phases in solid solutions with...An analysis of heterophase states was carried out for ferro-active solid solutions of the system(1-x-y)NaNbO_(3)-x KNbO_(3)-y CdNb_(2)O_(6).A complete stress relief at interfaces between phases in solid solutions with y=0.05 and x=0.10,0.40,and 0.45 is realized at the single-domain state of the tetragonal and orthorhombic phases.In solid solutions with y=0.05 and x=0.05 and 0.20,as well as with y=0.075 and 0.10,and x=0.15,the formation of a planar interphase boundary being parallel to a zero-net-strain plane occurs at the elastic matching of the single-domain tetragonal and polydomain orthorhombic phases.In contrast to this,at y=0.05 and x=0.25,0.30,and 0.35,the complete stress relief is associated with a co-existence of the single-domain orthorhombic and polydomain tetragonal phases,however in some cases,the tetragonal phase aims at a monodomainization.展开更多
Pure and superstoichiometric modified by 2 wt.%Bi_(2)O_(3) and 2 wt.%manganese oxide(Mn_(2)O_(3))ceramic samples of the binary system 0.71BiFeO_(3)-0.29BaTiO_(3) were fabricated using conventional ceramic technology b...Pure and superstoichiometric modified by 2 wt.%Bi_(2)O_(3) and 2 wt.%manganese oxide(Mn_(2)O_(3))ceramic samples of the binary system 0.71BiFeO_(3)-0.29BaTiO_(3) were fabricated using conventional ceramic technology by double solid-phase synthesis with following sintering.Mechanical activation of synthesized powders was carried out at the stage of manufacturing press powders prepared for sintering.X-ray analysis at room temperature showed that all studied ceramics have pseudo-cubic symmetry.Grain morphology,dielectric and piezoelectric properties of selected solid solutions were investigated.The modification increased the homogeneity of the material,dielectric constant and piezomodulus d_(33) and also resulted in a decrease in the dielectric loss tangent.The highest piezoelectric coefficient d_(33)=105 pC/N was obtained.Dielectric characteristics of ceramics revealed feroelectric relaxor behavior and region of diffuse phase transition from the paraelectric to ferroelectric phase in the temperature range of 740-770 K.展开更多
This paper discusses ways to search for lead-free functional materials for various applications.Using the example of the solid solution systems based on alkali metal niobates,the influence of the position on the phase...This paper discusses ways to search for lead-free functional materials for various applications.Using the example of the solid solution systems based on alkali metal niobates,the influence of the position on the phase diagram of the corresponding systems,the number of the components in them,and modification with mono-and combined metal oxides on their characteristics is shown.It has been established that the most effective in terms of piezoelectric characteristics are the solid solution systems in or near the morphotropic region,with 3 or 4 components.A number of materials have been developed to create highly sensitive electromechanical transducers,ultrasonic delay lines and other applications.展开更多
Solid solutions of the composition Ba_(1-x-y)(Mg,Ln)_(x)SryTiO_(3)(x=0.01;0.025;0.04;y=0.20;0.50;0.80;Ln=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tu,Yb)were prepared by two-stage solid-phase synthesis followed by sintering using...Solid solutions of the composition Ba_(1-x-y)(Mg,Ln)_(x)SryTiO_(3)(x=0.01;0.025;0.04;y=0.20;0.50;0.80;Ln=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tu,Yb)were prepared by two-stage solid-phase synthesis followed by sintering using conventional ceramic technology.The influence of rare-earth elements on the microstructure of the prepared ceramic samples was investigated.It was found that regardless of the type of modifiers introduced,the grain landscape of the studied solid solutions with different amounts of SrTiO_(3)is refined(in the initial system,the average grain size,d,at x=0.20 is 6μm;at x=0.50 is 4μm;at x=0.80 is 18μm)to crystallite sizes not exceeding(2-3)μm,and compacted.The using of mechanical activation procedures leads to an even greater decrease in the size and an increase in the density of ceramics.The increasing in the concentration of modifiers in each group(within the considered range of dopant variation)against the background of such a fine-grained structure has little effect on the dynamics of changes in d.It is concluded that it is advisable to use the data obtained in the development of functional materials based on BST/(Mg,Ln)and devices with the participation of these compositions.展开更多
The paper reports results on the complex study on ferroelectric ceramics that represent solid solutions containing components with a perovskite-type or columbite-type structure.Solid solutions of a three-component(1−x...The paper reports results on the complex study on ferroelectric ceramics that represent solid solutions containing components with a perovskite-type or columbite-type structure.Solid solutions of a three-component(1−x−y)NaNbO_(3)−xKNbO_(3)−yCdNb_(2)O_(6) system are manufactured at x=0.05-0.20 and y=0.10.Domain structures in ceramic grains are studied.The consistency between experimental and calculated results is examined for coexisting phases split into non-180°domains(mechanical twins)in the solid solution with x=0.15.A correlation between the internal structure(crystal,domain,granular,and defect)and fundamental electromechanical and polarization properties is stated for the studied three-component solid solutions.展开更多
This work presents the results of study of the electrophysical properties of composite polymer ceramics(1−x)[KNN-LTSN]-xPVDF at x=25 vol.%and x=50 vol.%in the temperature range of T=20-160℃and frequency range of f=2&...This work presents the results of study of the electrophysical properties of composite polymer ceramics(1−x)[KNN-LTSN]-xPVDF at x=25 vol.%and x=50 vol.%in the temperature range of T=20-160℃and frequency range of f=2×10^(1)-2×10^(6)Hz.The concentration dependence of piezomodules of the studied materials has been analyzed as a function of temperature.X-ray measurements have also been carried out.A model of description of revealed dielectric parameters dispersion in the material is presented.The nonclassical modified Havriliak-Negami model written for complex electrical conductivity has been used to describe the temperature-frequency properties.It is shown that the dielectric spectra of the studied composites include three relaxation processes in the temperature ranges of 40-80℃,80-120℃and 120-150℃,which were confirmed by the dynamics of changes in the dependences of g′(f),tgδ(f),M′(f),M″(f)and M″(M′).All three processes are almost exactly described by this model and well correlated with the studies by other researchers of the composites based on PVDF.The results of this work show that the use of such experimental model is suitable for describing the complex dielectric spectra of any nonlinear dielectrics including composite materials.展开更多
The solid solutions of the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system were produced by the conventional ceramic technology using mechanical activation of the synthesized product.It was found that in th...The solid solutions of the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system were produced by the conventional ceramic technology using mechanical activation of the synthesized product.It was found that in the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system at room temperature,a number of morphotropic phase transitions occur:rhombohedral!cubic!tetragonal!monoclinic phases.The introduction of a small amount of Na_(0.5)K_(0.5)NbO_(3) leads to an increase in the temperature stability of the dielectric properties of ceramics.A change in the relaxor properties of the solid solutions of the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system was shown.The increase in energy density and energy efficiency was found at additive 10 mol.%of Na_(0.5)K_(0.5)NbO_(3).展开更多
Ceramics of quasi-binary concentration section(x=0.50,0.1≤y≤0.2,Δy=0.025)of the ternary solid solution system(1−x−y)BiFeO_(3)-xPbFe_(0.5)Nb_(0.5)O_(3)-yPbTiO_(3)were prepared by the conventional solid-phase reactio...Ceramics of quasi-binary concentration section(x=0.50,0.1≤y≤0.2,Δy=0.025)of the ternary solid solution system(1−x−y)BiFeO_(3)-xPbFe_(0.5)Nb_(0.5)O_(3)-yPbTiO_(3)were prepared by the conventional solid-phase reaction method.By using X-ray diffraction technique,the phase diagram of the system was constructed,which was shown to contain the regions of cubic and tetragonal symmetry and the morphotropic phase boundary between them.Grain morphology,dielectric and piezoelectric properties of the selected solid solutions were investigated.The highest piezoelectric coefficient d_(33)=260 pC/N was obtained.Dielectric characteristics of ceramics revealed ferroelectric relaxor behavior,a region of diffuse phase transition from the paraelectric to ferroelectric phase in the temperature range of 350-500 K.展开更多
The paper discusses the features of the effect of modification with lithium carbonate on the dielectric dispersion of lead ferroniobate ceramics.The modifier has been previously shown to change the ways of the recryst...The paper discusses the features of the effect of modification with lithium carbonate on the dielectric dispersion of lead ferroniobate ceramics.The modifier has been previously shown to change the ways of the recrystallization sintering and therefore reduce the sintering temperature of the ceramics,increase their average grain size,and improve their dielectric and piezoelectric properties.In this study,the emphasis is placed on the analysis of the diffusion effects of the ferroelectric phase transition upon such mod-ification considered from the standpoint of the chemical specifics of the modifier and its location in the structure of the parent compound.展开更多
Study of the fatigue endurance and mechanical strength of solid solutions of the PZT-PZN-PMN system,modified with Ba and Sr,corresponding to the formula(Pb_(1-a_(1)-a_(2))Sr_(a_(1))Ba_(a_(1)))[Ti_(x)Zr_(y)<(Nb_(2/3...Study of the fatigue endurance and mechanical strength of solid solutions of the PZT-PZN-PMN system,modified with Ba and Sr,corresponding to the formula(Pb_(1-a_(1)-a_(2))Sr_(a_(1))Ba_(a_(1)))[Ti_(x)Zr_(y)<(Nb_(2/3)Zn_(1/3))(Nb_(2/3)Mg_(1/3))>_(1-x-y)]O_(3),with a_(1)=0.02÷0.12;Da_(1)=0.02,a_(2)=0.0036÷0.073;x=0.385÷0.430,y=0.402÷0.447 is presented.It is shown that the evolution of the polarization characteristics with an increase in the number of repolarization cycles,n,is characterized by two sections:slow fatigue and logarithmic evolution.It was found that an increase in the strontium content shifts the beginning of the logarithmic stage towards to the large n.It is shown that an increase in the average grain size decreases the mechanical strength.A conclusion is made about the expediency of using the obtained data in the development of devices operating in power modes.展开更多
The electromechanical responses of multicomponent solid solutions Pb_(0.95)Ba_(0.05)(Mg_(1/3)Nb_(2/3))_(0.471)(Zn_(1/3)Nb_(2/3))_(0.102)(Ni_(1/3)Nb_(2/3))_(0.152)Ti_(0.275)O_(3)in low and high electric fields were stu...The electromechanical responses of multicomponent solid solutions Pb_(0.95)Ba_(0.05)(Mg_(1/3)Nb_(2/3))_(0.471)(Zn_(1/3)Nb_(2/3))_(0.102)(Ni_(1/3)Nb_(2/3))_(0.152)Ti_(0.275)O_(3)in low and high electric fields were studied.In both cases,significant electromechanical responses are observed.In particular,the maximum values of the large-signal piezoelectric coefficient d_(33)reach 1600 m/V at very low values of the electric field(≈5 kV/cm).The observed features of the electromechanical responses of the studied ceramics are advantages in terms of their possible application in actuators.展开更多
This paper studies the dielectric spectra of solid solutions(SS)of the system(1−x−y)NaNbO_(3)-xKNbO_(3)-yCdNb_(2)O_(6) y=0.075,x=0.05÷0.30 in the temperature range(10÷900)K.The formation of a local maximum w...This paper studies the dielectric spectra of solid solutions(SS)of the system(1−x−y)NaNbO_(3)-xKNbO_(3)-yCdNb_(2)O_(6) y=0.075,x=0.05÷0.30 in the temperature range(10÷900)K.The formation of a local maximum was established in the interval(260÷300)K at small x values,which,as KNbO3 increases,is gradually blurred and becomes an inflection point.Detected in SS with x=0.05÷0.10,the shift of the maxima of dependencesε′/ε_(0)(T)andε″/ε_(0)(T),depending on the frequency of the electric field at the temperature ranges(300÷304)K and(258÷271)K,is not related to relaxation.This anomaly may indicate a crystallographic disorder to A and B positions.The conclusion is made about the expediency of using the obtained results for the development of functional ferroactive materials.展开更多
基金support of the Ministry of Science and Higher Education of the Russian Federation(State task in the field of scientific activity in 2023)Project No.FENW-2023-0010/(GZ0110/23-11-IF).
文摘An analysis of heterophase states was carried out for ferro-active solid solutions of the system(1-x-y)NaNbO_(3)-x KNbO_(3)-y CdNb_(2)O_(6).A complete stress relief at interfaces between phases in solid solutions with y=0.05 and x=0.10,0.40,and 0.45 is realized at the single-domain state of the tetragonal and orthorhombic phases.In solid solutions with y=0.05 and x=0.05 and 0.20,as well as with y=0.075 and 0.10,and x=0.15,the formation of a planar interphase boundary being parallel to a zero-net-strain plane occurs at the elastic matching of the single-domain tetragonal and polydomain orthorhombic phases.In contrast to this,at y=0.05 and x=0.25,0.30,and 0.35,the complete stress relief is associated with a co-existence of the single-domain orthorhombic and polydomain tetragonal phases,however in some cases,the tetragonal phase aims at a monodomainization.
基金financial support of the Ministry of Science and Higher Education of the Russian Federation(State task in the field of scientific activity.Project No.FENW-2023-0010/GZ0110/23-11-IF)。
文摘Pure and superstoichiometric modified by 2 wt.%Bi_(2)O_(3) and 2 wt.%manganese oxide(Mn_(2)O_(3))ceramic samples of the binary system 0.71BiFeO_(3)-0.29BaTiO_(3) were fabricated using conventional ceramic technology by double solid-phase synthesis with following sintering.Mechanical activation of synthesized powders was carried out at the stage of manufacturing press powders prepared for sintering.X-ray analysis at room temperature showed that all studied ceramics have pseudo-cubic symmetry.Grain morphology,dielectric and piezoelectric properties of selected solid solutions were investigated.The modification increased the homogeneity of the material,dielectric constant and piezomodulus d_(33) and also resulted in a decrease in the dielectric loss tangent.The highest piezoelectric coefficient d_(33)=105 pC/N was obtained.Dielectric characteristics of ceramics revealed feroelectric relaxor behavior and region of diffuse phase transition from the paraelectric to ferroelectric phase in the temperature range of 740-770 K.
基金financial support of the Ministry of Science and Higher Education of the Russian Federation.Project No.FENW-2023-0010/GZ0110/23-11-IF。
文摘This paper discusses ways to search for lead-free functional materials for various applications.Using the example of the solid solution systems based on alkali metal niobates,the influence of the position on the phase diagram of the corresponding systems,the number of the components in them,and modification with mono-and combined metal oxides on their characteristics is shown.It has been established that the most effective in terms of piezoelectric characteristics are the solid solution systems in or near the morphotropic region,with 3 or 4 components.A number of materials have been developed to create highly sensitive electromechanical transducers,ultrasonic delay lines and other applications.
基金The study was carried out with the financial support of the Ministry of Science and Higher Education of the Russian Federation(State task in the field of scientific activity,Scien-tific Project No.(0852-2020-0032)/(BAZ0110/20-3-07IF)).
文摘Solid solutions of the composition Ba_(1-x-y)(Mg,Ln)_(x)SryTiO_(3)(x=0.01;0.025;0.04;y=0.20;0.50;0.80;Ln=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tu,Yb)were prepared by two-stage solid-phase synthesis followed by sintering using conventional ceramic technology.The influence of rare-earth elements on the microstructure of the prepared ceramic samples was investigated.It was found that regardless of the type of modifiers introduced,the grain landscape of the studied solid solutions with different amounts of SrTiO_(3)is refined(in the initial system,the average grain size,d,at x=0.20 is 6μm;at x=0.50 is 4μm;at x=0.80 is 18μm)to crystallite sizes not exceeding(2-3)μm,and compacted.The using of mechanical activation procedures leads to an even greater decrease in the size and an increase in the density of ceramics.The increasing in the concentration of modifiers in each group(within the considered range of dopant variation)against the background of such a fine-grained structure has little effect on the dynamics of changes in d.It is concluded that it is advisable to use the data obtained in the development of functional materials based on BST/(Mg,Ln)and devices with the participation of these compositions.
基金support of the Ministry of Science and Higher Education of the Russian Federation(State Task in the Field of Scientific Activity,Scientific Project No.0852-2020-0032/BAZ0110/20-3-07IF).
文摘The paper reports results on the complex study on ferroelectric ceramics that represent solid solutions containing components with a perovskite-type or columbite-type structure.Solid solutions of a three-component(1−x−y)NaNbO_(3)−xKNbO_(3)−yCdNb_(2)O_(6) system are manufactured at x=0.05-0.20 and y=0.10.Domain structures in ceramic grains are studied.The consistency between experimental and calculated results is examined for coexisting phases split into non-180°domains(mechanical twins)in the solid solution with x=0.15.A correlation between the internal structure(crystal,domain,granular,and defect)and fundamental electromechanical and polarization properties is stated for the studied three-component solid solutions.
基金financially supported by the Ministry of Science and Higher Education of the Russian Federation:State Task in the Field of Scientific Activity,Scientific Project No.0852-2020-0032(BAZ0110/20-3-07IF)with the use of equipment of the Center for Collective Use“Integrated Centre of Scientific-Technological Equipment SSC RAS(Research,Development,Approval)”,Southern Scientific Centre of RAS(No.501994).The dielectric measurements were performed using the equipment of the Shared Research Facility Centre of SFedU,Research Institute of Physics.
文摘This work presents the results of study of the electrophysical properties of composite polymer ceramics(1−x)[KNN-LTSN]-xPVDF at x=25 vol.%and x=50 vol.%in the temperature range of T=20-160℃and frequency range of f=2×10^(1)-2×10^(6)Hz.The concentration dependence of piezomodules of the studied materials has been analyzed as a function of temperature.X-ray measurements have also been carried out.A model of description of revealed dielectric parameters dispersion in the material is presented.The nonclassical modified Havriliak-Negami model written for complex electrical conductivity has been used to describe the temperature-frequency properties.It is shown that the dielectric spectra of the studied composites include three relaxation processes in the temperature ranges of 40-80℃,80-120℃and 120-150℃,which were confirmed by the dynamics of changes in the dependences of g′(f),tgδ(f),M′(f),M″(f)and M″(M′).All three processes are almost exactly described by this model and well correlated with the studies by other researchers of the composites based on PVDF.The results of this work show that the use of such experimental model is suitable for describing the complex dielectric spectra of any nonlinear dielectrics including composite materials.
基金support of the Ministry of Science and Higher Education of the Federation(State task in the field of scientific activity in 2023)Project No.FENW-2023-0010/(GZ0110/23-11-IF).
文摘The solid solutions of the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system were produced by the conventional ceramic technology using mechanical activation of the synthesized product.It was found that in the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system at room temperature,a number of morphotropic phase transitions occur:rhombohedral!cubic!tetragonal!monoclinic phases.The introduction of a small amount of Na_(0.5)K_(0.5)NbO_(3) leads to an increase in the temperature stability of the dielectric properties of ceramics.A change in the relaxor properties of the solid solutions of the(1-x)Na_(0.5)Bi_(0.5)TiO_(3-x)Na_(0.5)K_(0.5)NbO_(3) system was shown.The increase in energy density and energy efficiency was found at additive 10 mol.%of Na_(0.5)K_(0.5)NbO_(3).
基金The study was carried out with the financial support of the Ministry of Science and Higher Education of the Russian Federation(State task in the field of scientific activity,scientific project No.0852-2020-0032)(BAZ0110/20-3-07IF)Work was performed using the equipment of the Center for Collective Use“Electromagnetic,Electromechanical and Thermal Properties of Solids”,Research Institute of Physics,Southern Federal University and Center for Collective Use of the Southern Scientific Center of the Russian Academy of Science(Rostov-on-Don,Russia).
文摘Ceramics of quasi-binary concentration section(x=0.50,0.1≤y≤0.2,Δy=0.025)of the ternary solid solution system(1−x−y)BiFeO_(3)-xPbFe_(0.5)Nb_(0.5)O_(3)-yPbTiO_(3)were prepared by the conventional solid-phase reaction method.By using X-ray diffraction technique,the phase diagram of the system was constructed,which was shown to contain the regions of cubic and tetragonal symmetry and the morphotropic phase boundary between them.Grain morphology,dielectric and piezoelectric properties of the selected solid solutions were investigated.The highest piezoelectric coefficient d_(33)=260 pC/N was obtained.Dielectric characteristics of ceramics revealed ferroelectric relaxor behavior,a region of diffuse phase transition from the paraelectric to ferroelectric phase in the temperature range of 350-500 K.
基金This work was financially supported by the Ministry of Science and Higher Education of the Russian Federation:State Task in the Field of Scientific Activity,Scientific Project No.0852-2020-0032(BAZ0110/20-3-07IF).
文摘The paper discusses the features of the effect of modification with lithium carbonate on the dielectric dispersion of lead ferroniobate ceramics.The modifier has been previously shown to change the ways of the recrystallization sintering and therefore reduce the sintering temperature of the ceramics,increase their average grain size,and improve their dielectric and piezoelectric properties.In this study,the emphasis is placed on the analysis of the diffusion effects of the ferroelectric phase transition upon such mod-ification considered from the standpoint of the chemical specifics of the modifier and its location in the structure of the parent compound.
基金The study was carried out with the financial support of the Ministry of Science and Higher Education of the Russian Federation State task in the field of scientific activity,scientific project No.(0852-2020-0032)/(BAZ0110/20-3-07IF).The equipment of the Center of Research Institute of Physics SFedU was used.
文摘Study of the fatigue endurance and mechanical strength of solid solutions of the PZT-PZN-PMN system,modified with Ba and Sr,corresponding to the formula(Pb_(1-a_(1)-a_(2))Sr_(a_(1))Ba_(a_(1)))[Ti_(x)Zr_(y)<(Nb_(2/3)Zn_(1/3))(Nb_(2/3)Mg_(1/3))>_(1-x-y)]O_(3),with a_(1)=0.02÷0.12;Da_(1)=0.02,a_(2)=0.0036÷0.073;x=0.385÷0.430,y=0.402÷0.447 is presented.It is shown that the evolution of the polarization characteristics with an increase in the number of repolarization cycles,n,is characterized by two sections:slow fatigue and logarithmic evolution.It was found that an increase in the strontium content shifts the beginning of the logarithmic stage towards to the large n.It is shown that an increase in the average grain size decreases the mechanical strength.A conclusion is made about the expediency of using the obtained data in the development of devices operating in power modes.
基金The electromechanical measurements were performed using the equipment of the Shared Research Facility Centre of SFedU,Research Institute of Physics.This work was financially supported by the Ministry of Science and Higher Education of the Russian Federation(State assignment in the field of scientific activity,Southern Federal University,2020).
文摘The electromechanical responses of multicomponent solid solutions Pb_(0.95)Ba_(0.05)(Mg_(1/3)Nb_(2/3))_(0.471)(Zn_(1/3)Nb_(2/3))_(0.102)(Ni_(1/3)Nb_(2/3))_(0.152)Ti_(0.275)O_(3)in low and high electric fields were studied.In both cases,significant electromechanical responses are observed.In particular,the maximum values of the large-signal piezoelectric coefficient d_(33)reach 1600 m/V at very low values of the electric field(≈5 kV/cm).The observed features of the electromechanical responses of the studied ceramics are advantages in terms of their possible application in actuators.
基金The research was supported by the Strategic Academic Leadership Program of the Southern Federal University(“Priority 2030”)This report is presented at the 10th Anniversary International Conference on“Physics and Mechanics of New Materials and Their Applications”(PHENMA 2021),Divnomorsk,Russia,May 23-27,2022.
文摘This paper studies the dielectric spectra of solid solutions(SS)of the system(1−x−y)NaNbO_(3)-xKNbO_(3)-yCdNb_(2)O_(6) y=0.075,x=0.05÷0.30 in the temperature range(10÷900)K.The formation of a local maximum was established in the interval(260÷300)K at small x values,which,as KNbO3 increases,is gradually blurred and becomes an inflection point.Detected in SS with x=0.05÷0.10,the shift of the maxima of dependencesε′/ε_(0)(T)andε″/ε_(0)(T),depending on the frequency of the electric field at the temperature ranges(300÷304)K and(258÷271)K,is not related to relaxation.This anomaly may indicate a crystallographic disorder to A and B positions.The conclusion is made about the expediency of using the obtained results for the development of functional ferroactive materials.
