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
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 properties studying results of ceramics based on strontium,calcium and sodium niobates,which vary from the conditions of synthesis,sintering,and mechanical processing,are presented.The evolution of the grain struc...The properties studying results of ceramics based on strontium,calcium and sodium niobates,which vary from the conditions of synthesis,sintering,and mechanical processing,are presented.The evolution of the grain structure of objects is traced depending on their phase filling during concentration changes in the composition and thermodynamic prehistory(preparation conditions).展开更多
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,sci-entific project No.0852-2020-0032),(BA30110/20-3-07IF).
文摘The properties studying results of ceramics based on strontium,calcium and sodium niobates,which vary from the conditions of synthesis,sintering,and mechanical processing,are presented.The evolution of the grain structure of objects is traced depending on their phase filling during concentration changes in the composition and thermodynamic prehistory(preparation conditions).
