The deformation process in the material volume under high-pressure torsion(HPT)was studied.As a model object for the observation of deformation process,we used a composite comprising a bronze matrix and niobium filame...The deformation process in the material volume under high-pressure torsion(HPT)was studied.As a model object for the observation of deformation process,we used a composite comprising a bronze matrix and niobium filaments.The arrangements of the niobium filaments in the bronze matrix and their size have regular geometry.This allows us to monitor and measure the displacement of the niobium filaments in the sample volume,which results from HTP.The bronze/niobium composite samples were subjected to HPT at room temperature and 6 GPa,and the number of revolutions N=1/4,1/2,1,2,3 and 5.It was shown that HPT with revolution number of 1 leads to the 360° rotation of entire sample volume without sample slippage.Similar deformational behavior during HPT can be expected for high-ductility metallic materials.The increase in the number of revolutions more than 2 leads to twisting the niobium filaments in the sample volume and the formation of 'vortex' multilayer structure.The mechanisms for the formation of such structures were discussed.展开更多
The Boltzmann local physical kinetics forecasts the destruction of SC regime because of the heat movement of particles. Then, the most fundamental distinction between a strange metal and a conventional metal is the ab...The Boltzmann local physical kinetics forecasts the destruction of SC regime because of the heat movement of particles. Then, the most fundamental distinction between a strange metal and a conventional metal is the absence of well-defined quasi-particles. Here, we show that the mentioned “quasi-particles” are solitons, which are formed as a result of self-organization of ionized matter. Shortcomings of the Boltzmann physical kinetics consist in the local description of the transport processes on the level of infinitely small physical volumes as elements of diagnostics. The non-local physics leads to the theory superconductivity including the high temperature diapason. The generalized non-local non-stationary London’s formula is derived.展开更多
Shortcomings of the Boltzmann physical kinetics and the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics are considered. From the position of nonlocal p...Shortcomings of the Boltzmann physical kinetics and the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics are considered. From the position of nonlocal physics, the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger equation is a local equation;this fact leads to the great shortcomings of the linear Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics. Nonlocal nonlinear quantum mechanics is considered using the wave function terminology.展开更多
It is considered three phases of development of a tropical cyclone: the origin, the steady-state regime and the termination, coinciding with three phases of self-oscillatory process: oscillation buid-up, dynamic balan...It is considered three phases of development of a tropical cyclone: the origin, the steady-state regime and the termination, coinciding with three phases of self-oscillatory process: oscillation buid-up, dynamic balance and failure of self-oscillations. The rough size of energy of a cyclone, as column of air rotating with high speed, at initial and final stages of development and comparison of the received sizes with nuclear and hydrogen bombs is calculated. The model of the electronic oscillator with negative active conductivity by the numerical solution of the equation of the Van-der-Pol is analyzed. Formal coincidence of transient in this model with increase of capacity of vortical air formation, that allows to make mnemonic model of a cyclone in the form of volume self-oscillatory system is shown. The numerical solution of the made equations allows to construct schedules of dynamic process for each of particles of the investigated environment. The general recipe on restraint of development of a cyclone by compulsory entering into it of attenuation is given. Realization of this recipe by means of group of platforms with powerful wind-electrogenerator and the fans and uses of a principle of negative feedback is shown. The results of laboratory experiment confirming idea, taken as a principle struggle against an arising air whirlwind, by transformation of a laminar stream in chaotic, turbulent are resulted. For fuller check offered a wind-energetic method of struggle against a cyclone carrying out of more scale experiment is necessary.展开更多
Multidimensional noncommutative Laplace transforms over octonions are studied. Theorems about direct and inverse transforms and other properties of the Laplace transforms over the Cayley-Dickson algebras are proved. A...Multidimensional noncommutative Laplace transforms over octonions are studied. Theorems about direct and inverse transforms and other properties of the Laplace transforms over the Cayley-Dickson algebras are proved. Applications to partial differential equations including that of elliptic, parabolic and hyperbolic type are investigated. Moreover, partial differential equations of higher order with real and complex coefficients and with variable coefficients with or without boundary conditions are considered.展开更多
The purpose of this review is to apply geometric frameworks in identification problems. In contrast to the qualitative theory of dynamical systems (DSQT), the chaos and catastrophes, researches on the application of g...The purpose of this review is to apply geometric frameworks in identification problems. In contrast to the qualitative theory of dynamical systems (DSQT), the chaos and catastrophes, researches on the application of geometric frameworks have not </span><span style="font-family:Verdana;">been </span><span style="font-family:Verdana;">performed in identification problems. The direct transfer of DSQT ideas is inefficient through the peculiarities of identification systems. In this paper, the attempt </span><span style="font-family:Verdana;">is </span><span style="font-family:Verdana;">made based on the latest researches in this field. A methodology for the synthesis of geometric frameworks (GF) </span><span style="font-family:Verdana;">is </span><span style="font-family:Verdana;">propose</span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;">, which reflects features of nonlinear systems. Methods based on GF analysis </span><span style="font-family:Verdana;">are </span><span style="font-family:Verdana;">developed for the decision-making on properties and structure of nonlinear systems. The problem solution of structural identifiability </span><span style="font-family:Verdana;">is </span><span style="font-family:Verdana;">obtain</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;"> for nonlinear systems under uncertainty.展开更多
The old classical problems of theoretical physics are revisited from the point of view of nonlocal physics. Nonlocal physics leads to very complicated mathematical apparatus. Here, we explain the main principles of no...The old classical problems of theoretical physics are revisited from the point of view of nonlocal physics. Nonlocal physics leads to very complicated mathematical apparatus. Here, we explain the main principles of nonlocal physics using transparent considerations and animations.展开更多
The new inversion formula of the Laplace transform is considered. In the formula we use only the positive values ofx SiCoLT（x） = c S（x）, L（S（x）） = T（x）, c = const., x 〉 O,from the real axis. Si is the sinus...The new inversion formula of the Laplace transform is considered. In the formula we use only the positive values ofx SiCoLT（x） = c S（x）, L（S（x）） = T（x）, c = const., x 〉 O,from the real axis. Si is the sinus transform, Co is the cosines transform of Fourier and L is the Laplace transform.展开更多
Over the past decade,the power conversion efficiency of halide perovskite solar cells has shown a rapid increase to 26.1%.The significant efficiency growth and the relative simplification of the technology for obtaini...Over the past decade,the power conversion efficiency of halide perovskite solar cells has shown a rapid increase to 26.1%.The significant efficiency growth and the relative simplification of the technology for obtaining thin-film solar cells due to liquid printing methods determine the high potential for the low-cost perovskite solar cells manufacturing.However,efficient use of cell geometry is comparable to the size of standard crystalline-Si wafers(156:156 mm and more).Therefore,modular geometry similar to amorphous-Si solar cell approaches is used to scale perovskite solar cells.Serial electrical connection of thin-film cells requires precise processing of the conductive layers that form the device p-i-n structure.The subject of research is the development of a full pulsed laser scribing cycle for inverted perovskite solar cells.In this work,we propose a study of a laser-patterning technology In_(2)O_(3):SnO_(2)(ITO)conductive layer and a photoactive perovskite layer Cs0,2(CH(NH_(2))_(2))_(0,8)PbI_(3).Process regimes of transparent conducting electrodes based on ITO and halide perovskite layer Cs_(0,2)(CH(NH_(2))_(2))_(0,8)PbI_(3)laser patterning were obtained.The optimal parameters for the multipass mode processing of ITO and perovskite layer were determined.The cell was electrically isolated at a scribe line width of 30μm.展开更多
It's urgent to develop benzocyclobutene(BCB)-based polymers with low curing temperature for temperature-sensitive applications such as liquid crystal displays(LCDs)and flexible electronics.Herein,the effect of sub...It's urgent to develop benzocyclobutene(BCB)-based polymers with low curing temperature for temperature-sensitive applications such as liquid crystal displays(LCDs)and flexible electronics.Herein,the effect of substituents on the ring-opening behavior of BCB derivatives was investigated.The ring-opening activation energy barriers(ΔGA)of BCB derivatives with one or two substituents on the four-membered alkyl ring were systematically calculated using the B3LYP function.Both mono-and di-substituted BCBs adopted the conrotatory ring-opening process,obeying the Woodward-Hoffmann's Rules upon heating.The mono-/di-substituted BCBs exhibited 8.2%—69%lowerΔGA compared with BCB,attributed to the electronic effects of the substituents.Disubstituted BCBs with both electron-donating and electron-withdrawing groups,e.g.,1-NH_(2)-8-NO_(2)-BCB,demonstrated the lowestΔGA.In addition,BCB derivatives with amide/ester/acyloxy group modified on C1 position were synthesized as model molecules,and their ring-opening temperature can be decreased by 20℃ compared to the unsubstituted one,also consistent with our calculation results.This work combined theoretical calculation methods with experimental results to provide valuable insights into the design and synthesis of BCB derivatives and next-generation BCB functional packaging materials with low ring-opening temperature.展开更多
Polyetheretherketone(PEEK)is an alternative to metallic implants and a material of choice in many applications,including orthopedic,spinal,trauma,and dental.While titanium(Ti)and Ti-alloys are widely used in many intr...Polyetheretherketone(PEEK)is an alternative to metallic implants and a material of choice in many applications,including orthopedic,spinal,trauma,and dental.While titanium(Ti)and Ti-alloys are widely used in many intraosseous implants due to its biocompatibility and ability to osseointegrate,negatives include stiffness which contributes to shear stress,radio-opacity,and Ti-sensitivity.Many surgeons prefer to use PEEK due to its biocompatibility,similar elasticity to bone,and radiolucency,however,due to its inert properties,it fails to fully integrate with bone.Accelerated Neutral Atom Beam(ANAB)technology has been successfully employed to demonstrate enhanced bioactivity of PEEK both in vitro and in vivo.In this study,we further characterize surfaces of PEEK modified by ANAB as well as elucidate attachment and genetic effects of dental pulp stem cells(DPSC)exposed to these surfaces.ANAB modification resulted in decreased contact angle at 72.9±4.5°as compared to 92.4±8.5°for control(p<0.01)and a decreased average surface roughness,however with a nano-textured surface profile.ANAB treatment also increased the ability of DPSC attachment and proliferation with considerable genetic differences showing earlier progression towards osteogenic differentiation.This surface modification is achieved without adding a coating or changing the chemical composition of the PEEK material.Taken together,we show that ANAB processing of PEEK surface enhances the bioactivity of implantable medical devices without an additive or a coating.展开更多
In this review,our recent results on the electron-beam domain writing(EBDW)on the nonpolar surfaces of LiNbO_(3) crystals of different compositions are presented.Under EB irradiation of the nonpolar surfaces,domains n...In this review,our recent results on the electron-beam domain writing(EBDW)on the nonpolar surfaces of LiNbO_(3) crystals of different compositions are presented.Under EB irradiation of the nonpolar surfaces,domains nucleated in irradiation points grow frontally along the polar Z-direction in a thin(of microns in thickness)surface layer;the driving force is the tangential component of space-charge fields induced by EB in irradiation points.This geometry of the experiment provides a possibility of three-dimensional(3D)characterization of domain patterns using the combination of atomic force microscopy(AFM)and second harmonic generation(SHG)confocal microscopy methods.The obtained results permitted us to relate the main characteristics of domain formation(the domain sizes and velocity Vf of the frontal motion)to the irradiation conditions(the accelerating voltage U of scanning electron microscopy(SEM),EB current I,the inserted charge Q).The domain depth Td is controlled by U via the electron penetration depth;the domain length Ld increases linearly with Q owing to the domain frontal growth by the viscous friction law.The electron emission coefficientaffects the domain formation due to the fundamental dependence ofon U.In the framework of current approach to EB charging of insulators,the effect of an enhanced conductance on EBDW characteristics is analyzed.The difference between EBDW characteristics observed in varied LiNbO_(3) compositions is discussed in the framework of the intrinsic defect structure of LiNbO_(3).The obtained results extend the possibility of EBDW application to a wider range of crystals.展开更多
The comparative analysis of the dielectric properties of bismuth-containing pyrochlores with different manifestation of atomic order/disorder was carried out.We examined the dielectric properties(including behavior in...The comparative analysis of the dielectric properties of bismuth-containing pyrochlores with different manifestation of atomic order/disorder was carried out.We examined the dielectric properties(including behavior in electric fields)of two pyrochlore compounds:BZN(presumably a composition close to Bi_(1.5)Zn_(0.5)Nb_(1.5)O_(6.5))ceramics with chemical disorder in both A and B cation sublattices and Bi_(2)Ti_(2)O_(7)single crystal with fully chemical ordered structure.The fundamental differences between the dielectric properties of the BZN ceramics and Bi_(2)Ti_(2)O_(7)single crystal were shown.In particular,in the dielectric relaxation behavior(which cannot be described via Arrhenius law in the Bi_(2)Ti_(2)O_(7))or in the influence of the electric fields on the dielectric permittivity(split-ting of the field-cooled and zero-field-cooled behaviors was observed for Bi_(2)Ti_(2)O_(7)below estimated freezing temperature).The results of this study highlights the special role of Bi_(2)Ti_(2)O_(7)as a candidate material for studying aspects of geometric frustration related with pyrochlore structure in non-magnetic medium and specifies the future directions of research.展开更多
基金financial support from the Ministry of Science and Higher Education of the Russian Federation in the framework of Increase Competitiveness Program of NUST “MISi S” (No. K2-2019-008)
文摘The deformation process in the material volume under high-pressure torsion(HPT)was studied.As a model object for the observation of deformation process,we used a composite comprising a bronze matrix and niobium filaments.The arrangements of the niobium filaments in the bronze matrix and their size have regular geometry.This allows us to monitor and measure the displacement of the niobium filaments in the sample volume,which results from HTP.The bronze/niobium composite samples were subjected to HPT at room temperature and 6 GPa,and the number of revolutions N=1/4,1/2,1,2,3 and 5.It was shown that HPT with revolution number of 1 leads to the 360° rotation of entire sample volume without sample slippage.Similar deformational behavior during HPT can be expected for high-ductility metallic materials.The increase in the number of revolutions more than 2 leads to twisting the niobium filaments in the sample volume and the formation of 'vortex' multilayer structure.The mechanisms for the formation of such structures were discussed.
文摘The Boltzmann local physical kinetics forecasts the destruction of SC regime because of the heat movement of particles. Then, the most fundamental distinction between a strange metal and a conventional metal is the absence of well-defined quasi-particles. Here, we show that the mentioned “quasi-particles” are solitons, which are formed as a result of self-organization of ionized matter. Shortcomings of the Boltzmann physical kinetics consist in the local description of the transport processes on the level of infinitely small physical volumes as elements of diagnostics. The non-local physics leads to the theory superconductivity including the high temperature diapason. The generalized non-local non-stationary London’s formula is derived.
文摘Shortcomings of the Boltzmann physical kinetics and the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics are considered. From the position of nonlocal physics, the Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger equation is a local equation;this fact leads to the great shortcomings of the linear Schr<span style="font-size:12px;white-space:nowrap;">ö</span>dinger wave mechanics. Nonlocal nonlinear quantum mechanics is considered using the wave function terminology.
文摘It is considered three phases of development of a tropical cyclone: the origin, the steady-state regime and the termination, coinciding with three phases of self-oscillatory process: oscillation buid-up, dynamic balance and failure of self-oscillations. The rough size of energy of a cyclone, as column of air rotating with high speed, at initial and final stages of development and comparison of the received sizes with nuclear and hydrogen bombs is calculated. The model of the electronic oscillator with negative active conductivity by the numerical solution of the equation of the Van-der-Pol is analyzed. Formal coincidence of transient in this model with increase of capacity of vortical air formation, that allows to make mnemonic model of a cyclone in the form of volume self-oscillatory system is shown. The numerical solution of the made equations allows to construct schedules of dynamic process for each of particles of the investigated environment. The general recipe on restraint of development of a cyclone by compulsory entering into it of attenuation is given. Realization of this recipe by means of group of platforms with powerful wind-electrogenerator and the fans and uses of a principle of negative feedback is shown. The results of laboratory experiment confirming idea, taken as a principle struggle against an arising air whirlwind, by transformation of a laminar stream in chaotic, turbulent are resulted. For fuller check offered a wind-energetic method of struggle against a cyclone carrying out of more scale experiment is necessary.
文摘Multidimensional noncommutative Laplace transforms over octonions are studied. Theorems about direct and inverse transforms and other properties of the Laplace transforms over the Cayley-Dickson algebras are proved. Applications to partial differential equations including that of elliptic, parabolic and hyperbolic type are investigated. Moreover, partial differential equations of higher order with real and complex coefficients and with variable coefficients with or without boundary conditions are considered.
文摘The purpose of this review is to apply geometric frameworks in identification problems. In contrast to the qualitative theory of dynamical systems (DSQT), the chaos and catastrophes, researches on the application of geometric frameworks have not </span><span style="font-family:Verdana;">been </span><span style="font-family:Verdana;">performed in identification problems. The direct transfer of DSQT ideas is inefficient through the peculiarities of identification systems. In this paper, the attempt </span><span style="font-family:Verdana;">is </span><span style="font-family:Verdana;">made based on the latest researches in this field. A methodology for the synthesis of geometric frameworks (GF) </span><span style="font-family:Verdana;">is </span><span style="font-family:Verdana;">propose</span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;">, which reflects features of nonlinear systems. Methods based on GF analysis </span><span style="font-family:Verdana;">are </span><span style="font-family:Verdana;">developed for the decision-making on properties and structure of nonlinear systems. The problem solution of structural identifiability </span><span style="font-family:Verdana;">is </span><span style="font-family:Verdana;">obtain</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;"> for nonlinear systems under uncertainty.
文摘The old classical problems of theoretical physics are revisited from the point of view of nonlocal physics. Nonlocal physics leads to very complicated mathematical apparatus. Here, we explain the main principles of nonlocal physics using transparent considerations and animations.
文摘The new inversion formula of the Laplace transform is considered. In the formula we use only the positive values ofx SiCoLT（x） = c S（x）, L（S（x）） = T（x）, c = const., x 〉 O,from the real axis. Si is the sinus transform, Co is the cosines transform of Fourier and L is the Laplace transform.
基金support from the Ministry of Science and Higher Education of the Russian Federation in the framework of the Russian Science Foundation Grant No.21-19-00853R.I.,P.G.and A.I.acknowledge the financial support of“Theoretical and methodological framework for digital transformation in radiology”,(USIS No.123031400118-0)in accordance with the Order No.1196 dated December 21,2022"On approval of state assignments funded by means of allocations from the budget of the city of Moscow to the state budgetary(autonomous)institutions subordinate to the Moscow Health Care Department,for 2023 and the planned period of 2024 and 2025"issued by the Moscow Health Care Department.
文摘Over the past decade,the power conversion efficiency of halide perovskite solar cells has shown a rapid increase to 26.1%.The significant efficiency growth and the relative simplification of the technology for obtaining thin-film solar cells due to liquid printing methods determine the high potential for the low-cost perovskite solar cells manufacturing.However,efficient use of cell geometry is comparable to the size of standard crystalline-Si wafers(156:156 mm and more).Therefore,modular geometry similar to amorphous-Si solar cell approaches is used to scale perovskite solar cells.Serial electrical connection of thin-film cells requires precise processing of the conductive layers that form the device p-i-n structure.The subject of research is the development of a full pulsed laser scribing cycle for inverted perovskite solar cells.In this work,we propose a study of a laser-patterning technology In_(2)O_(3):SnO_(2)(ITO)conductive layer and a photoactive perovskite layer Cs0,2(CH(NH_(2))_(2))_(0,8)PbI_(3).Process regimes of transparent conducting electrodes based on ITO and halide perovskite layer Cs_(0,2)(CH(NH_(2))_(2))_(0,8)PbI_(3)laser patterning were obtained.The optimal parameters for the multipass mode processing of ITO and perovskite layer were determined.The cell was electrically isolated at a scribe line width of 30μm.
基金supported by the National Natural Science Foundation of China(Nos.22075298,2022000168)Beijing Municipal Natural Science Foundation(No,2212053).
文摘It's urgent to develop benzocyclobutene(BCB)-based polymers with low curing temperature for temperature-sensitive applications such as liquid crystal displays(LCDs)and flexible electronics.Herein,the effect of substituents on the ring-opening behavior of BCB derivatives was investigated.The ring-opening activation energy barriers(ΔGA)of BCB derivatives with one or two substituents on the four-membered alkyl ring were systematically calculated using the B3LYP function.Both mono-and di-substituted BCBs adopted the conrotatory ring-opening process,obeying the Woodward-Hoffmann's Rules upon heating.The mono-/di-substituted BCBs exhibited 8.2%—69%lowerΔGA compared with BCB,attributed to the electronic effects of the substituents.Disubstituted BCBs with both electron-donating and electron-withdrawing groups,e.g.,1-NH_(2)-8-NO_(2)-BCB,demonstrated the lowestΔGA.In addition,BCB derivatives with amide/ester/acyloxy group modified on C1 position were synthesized as model molecules,and their ring-opening temperature can be decreased by 20℃ compared to the unsubstituted one,also consistent with our calculation results.This work combined theoretical calculation methods with experimental results to provide valuable insights into the design and synthesis of BCB derivatives and next-generation BCB functional packaging materials with low ring-opening temperature.
基金partially performed with the financial support of the Ministry of Education and Science of the Russian Federation(RFMEFI57417X0136)。
文摘Polyetheretherketone(PEEK)is an alternative to metallic implants and a material of choice in many applications,including orthopedic,spinal,trauma,and dental.While titanium(Ti)and Ti-alloys are widely used in many intraosseous implants due to its biocompatibility and ability to osseointegrate,negatives include stiffness which contributes to shear stress,radio-opacity,and Ti-sensitivity.Many surgeons prefer to use PEEK due to its biocompatibility,similar elasticity to bone,and radiolucency,however,due to its inert properties,it fails to fully integrate with bone.Accelerated Neutral Atom Beam(ANAB)technology has been successfully employed to demonstrate enhanced bioactivity of PEEK both in vitro and in vivo.In this study,we further characterize surfaces of PEEK modified by ANAB as well as elucidate attachment and genetic effects of dental pulp stem cells(DPSC)exposed to these surfaces.ANAB modification resulted in decreased contact angle at 72.9±4.5°as compared to 92.4±8.5°for control(p<0.01)and a decreased average surface roughness,however with a nano-textured surface profile.ANAB treatment also increased the ability of DPSC attachment and proliferation with considerable genetic differences showing earlier progression towards osteogenic differentiation.This surface modification is achieved without adding a coating or changing the chemical composition of the PEEK material.Taken together,we show that ANAB processing of PEEK surface enhances the bioactivity of implantable medical devices without an additive or a coating.
基金supported by the Federal Agency of Scientific Organizations(Agreement No.007-State Task/3363/26)in part of AFM experiments and by the Russian Science Foundation(Project No.16-0200439a)in part of SEM experiments and analysis of the experimental dataThe equipment of the Shared Research Center supported by the Ministry of Education and Science(Project No.RFMEFI62114X0005)was used in experiments。
文摘In this review,our recent results on the electron-beam domain writing(EBDW)on the nonpolar surfaces of LiNbO_(3) crystals of different compositions are presented.Under EB irradiation of the nonpolar surfaces,domains nucleated in irradiation points grow frontally along the polar Z-direction in a thin(of microns in thickness)surface layer;the driving force is the tangential component of space-charge fields induced by EB in irradiation points.This geometry of the experiment provides a possibility of three-dimensional(3D)characterization of domain patterns using the combination of atomic force microscopy(AFM)and second harmonic generation(SHG)confocal microscopy methods.The obtained results permitted us to relate the main characteristics of domain formation(the domain sizes and velocity Vf of the frontal motion)to the irradiation conditions(the accelerating voltage U of scanning electron microscopy(SEM),EB current I,the inserted charge Q).The domain depth Td is controlled by U via the electron penetration depth;the domain length Ld increases linearly with Q owing to the domain frontal growth by the viscous friction law.The electron emission coefficientaffects the domain formation due to the fundamental dependence ofon U.In the framework of current approach to EB charging of insulators,the effect of an enhanced conductance on EBDW characteristics is analyzed.The difference between EBDW characteristics observed in varied LiNbO_(3) compositions is discussed in the framework of the intrinsic defect structure of LiNbO_(3).The obtained results extend the possibility of EBDW application to a wider range of crystals.
基金The authors are grateful to L.A.Shilkina for X-ray phase analysis of the BZN samples.The reported study was funded by Russian Science Foundation(RSF)-research projects no.20-72-00086(BZN ceramics preparation,dielectric mea-surements)At RTU MIREA,the work was supported by the Ministry of Science and Higher Education of Russia(project FSFZ 0706-2020-2022,Bi2Ti2O7 single crystal growth),the equipment of the Center for Collective Use of RTU MIREA was used.
文摘The comparative analysis of the dielectric properties of bismuth-containing pyrochlores with different manifestation of atomic order/disorder was carried out.We examined the dielectric properties(including behavior in electric fields)of two pyrochlore compounds:BZN(presumably a composition close to Bi_(1.5)Zn_(0.5)Nb_(1.5)O_(6.5))ceramics with chemical disorder in both A and B cation sublattices and Bi_(2)Ti_(2)O_(7)single crystal with fully chemical ordered structure.The fundamental differences between the dielectric properties of the BZN ceramics and Bi_(2)Ti_(2)O_(7)single crystal were shown.In particular,in the dielectric relaxation behavior(which cannot be described via Arrhenius law in the Bi_(2)Ti_(2)O_(7))or in the influence of the electric fields on the dielectric permittivity(split-ting of the field-cooled and zero-field-cooled behaviors was observed for Bi_(2)Ti_(2)O_(7)below estimated freezing temperature).The results of this study highlights the special role of Bi_(2)Ti_(2)O_(7)as a candidate material for studying aspects of geometric frustration related with pyrochlore structure in non-magnetic medium and specifies the future directions of research.
