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
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
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
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).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.
