High-performance dielectric tunable materials with both high dielectric tunability and low dielectric loss are urgently needed for new-generation electronic tunable devices.In the present study,a new system,(Ba_(0.675...High-performance dielectric tunable materials with both high dielectric tunability and low dielectric loss are urgently needed for new-generation electronic tunable devices.In the present study,a new system,(Ba_(0.675)Sr_(0.325))_(1−x)La_(x)Ti_(1−x)MnxO_(3)(x=0.25%,0.5%,0.75%,and 1.0%),was designed.The acceptor dopant Mn was added to lower dielectric loss,while the donor dopant La was introduced to enhance dielectric tunability.The samples were prepared using the conventional solid-state(CS)reaction method and the semi-solution(SS)method.The experimental results showed that the morphology of the ceramics was optimized by further improving the processing procedure.Dense microstructures,homogeneous grains,and uniform dopant distributions could be achieved successfully by the semi-solution method.Moreover,a significant enhancement in the tunable properties was realized owing to the improved microstructure mentioned above.The optimum tunable properties occurred in the samples prepared by the semi-solution method at x=0.75%,with a high dielectric tunability of 85.0%,a low dielectric loss of 0.0011,and an excellent figure of merit(FOM)of 773.The tunable properties of(Ba,Sr)TiO_(3)(BST)ceramics were even superior to those of lead-based materials,with an FOM of approximately 700.All the results suggested that the semi-solution method rendered BST ceramics more promising for applications in tunable devices.展开更多
(Ba0.3Sr0.7)x(Bi0.5Na0.5)1-xTiO3(BSxBNT,x=0.3–V0.8)ceramics were prepared to investigate their structure,dielectric and ferroelectric properties.BSxBNT ceramics possess pure perovskite structure accompanied from a te...(Ba0.3Sr0.7)x(Bi0.5Na0.5)1-xTiO3(BSxBNT,x=0.3–V0.8)ceramics were prepared to investigate their structure,dielectric and ferroelectric properties.BSxBNT ceramics possess pure perovskite structure accompanied from a tetragonal symmetry to pseudo-cubic one with the increase of x value,being confirmed by X-ray diffraction(XRD)and Raman results.The Tm corresponding to a temperature in the vicinity of maximum dielectric constant gradually decreases from 110℃(x=0.3)to-45℃(x=0.8),across Tm=36℃(x=0.5)with a maximum dielectric constant(ɛr=5920@1 kHz)around room temperature.The saturated polarization Ps gradually while the remnant polarization Pr sharply decreases with the increase of x value,making the P-E hysteresis loop of BSxBNT ceramics goes slim.A maximum difference between Ps and Pr(Ps-Pr)is obtained for BSxBNT ceramics with x=0.5,at which a high recoverable energy density(Wrec=1.04 J/cm3)is achieved under an applied electric field of 100 kV/cm with an efficiency ofη=77%.Meanwhile,the varied temperature P-E loops,fatigue measurements,and electric breakdown characteristics for the sample with x=0.5 indicate that it is promising for pulsed power energy storage capacitor candidate materials.展开更多
Relaxor ferroelectric ceramics have very high dielectric constant(e)but relatively low electrical breakdown strength(Eb),while glass-ceramics exhibit higher E,due to the more uniformly dispersed amorphous phases and s...Relaxor ferroelectric ceramics have very high dielectric constant(e)but relatively low electrical breakdown strength(Eb),while glass-ceramics exhibit higher E,due to the more uniformly dispersed amorphous phases and submicrocrystals/nanocrystals inside.How to effectively combine the advantages of both relaxor ferroelectric ceramics and glass-ceramics is of great significance for the development of new dielectric materials with high energy storage performance.In this work,we firstly prepared BaO-SrO-Bi_(2)O_(3)-Na_(2)0-TiO_(2)-Al_(2)O_(3)-SiO_(2)(abbreviated as GS)glass powders,and then fabricated(Ba_(0.3)Sr_(0.7))_(0.5)(Bi_(0.5)Na_(0.5))_(0.5)TiO_(3)+x wt%GS ceramic composites(abbreviated as BSo.sBNT-xGS,x=0,2,6,10,14,16,and 18).Submicrocrystals/nanocrystals with a similar composition to BSo.sBNT were crystalized from the glass,ensuring the formation of uniform core-shell structure in BSo.sBNT-xGS relaxor ferroelectric ceramic/glass-ceramic composites.When the addition amount of GS was 14 wt%,the composite possessed both high&r(>3200 at 1 kHz)and high E,(~170 kV/cm)at room temperature,and their recoverable energy storage density and efficiency were Wrec=2.1 J/cm’and n=65.2%,respectively.The BSo.sBNT-14GS composite also had several attractive properties such as good temperature,frequency,cycle stability,and fast charge-discharge speed.This work provides insights into the relaxor ceramic/glass-ceramic composites for pulsed power capacitors and sheds light on the utilization of the hybrid systems.展开更多
基金supported by the National Natural Science Foundation of China(No.U1966602).
文摘High-performance dielectric tunable materials with both high dielectric tunability and low dielectric loss are urgently needed for new-generation electronic tunable devices.In the present study,a new system,(Ba_(0.675)Sr_(0.325))_(1−x)La_(x)Ti_(1−x)MnxO_(3)(x=0.25%,0.5%,0.75%,and 1.0%),was designed.The acceptor dopant Mn was added to lower dielectric loss,while the donor dopant La was introduced to enhance dielectric tunability.The samples were prepared using the conventional solid-state(CS)reaction method and the semi-solution(SS)method.The experimental results showed that the morphology of the ceramics was optimized by further improving the processing procedure.Dense microstructures,homogeneous grains,and uniform dopant distributions could be achieved successfully by the semi-solution method.Moreover,a significant enhancement in the tunable properties was realized owing to the improved microstructure mentioned above.The optimum tunable properties occurred in the samples prepared by the semi-solution method at x=0.75%,with a high dielectric tunability of 85.0%,a low dielectric loss of 0.0011,and an excellent figure of merit(FOM)of 773.The tunable properties of(Ba,Sr)TiO_(3)(BST)ceramics were even superior to those of lead-based materials,with an FOM of approximately 700.All the results suggested that the semi-solution method rendered BST ceramics more promising for applications in tunable devices.
基金This work was financially supported by National Natural Science Foundation of China(51767010)Science&Technology Key Research Project of Jiangxi Provincial Education Department(GJJ170760)Graduate Student Innovation Fund of Jiangxi Province(YC2018-S295).
文摘(Ba0.3Sr0.7)x(Bi0.5Na0.5)1-xTiO3(BSxBNT,x=0.3–V0.8)ceramics were prepared to investigate their structure,dielectric and ferroelectric properties.BSxBNT ceramics possess pure perovskite structure accompanied from a tetragonal symmetry to pseudo-cubic one with the increase of x value,being confirmed by X-ray diffraction(XRD)and Raman results.The Tm corresponding to a temperature in the vicinity of maximum dielectric constant gradually decreases from 110℃(x=0.3)to-45℃(x=0.8),across Tm=36℃(x=0.5)with a maximum dielectric constant(ɛr=5920@1 kHz)around room temperature.The saturated polarization Ps gradually while the remnant polarization Pr sharply decreases with the increase of x value,making the P-E hysteresis loop of BSxBNT ceramics goes slim.A maximum difference between Ps and Pr(Ps-Pr)is obtained for BSxBNT ceramics with x=0.5,at which a high recoverable energy density(Wrec=1.04 J/cm3)is achieved under an applied electric field of 100 kV/cm with an efficiency ofη=77%.Meanwhile,the varied temperature P-E loops,fatigue measurements,and electric breakdown characteristics for the sample with x=0.5 indicate that it is promising for pulsed power energy storage capacitor candidate materials.
基金supported by the National Natural Science Foundation of China(52267002)Natural Science Foundation of Jiangxi Province(20212ACB204010)+1 种基金Science&Technology Research Project of Jiangxi Provincial Education Department(GJJ211301)the Graduate Innovation Fund of Jiangxi Province(YC2021-S527).
文摘Relaxor ferroelectric ceramics have very high dielectric constant(e)but relatively low electrical breakdown strength(Eb),while glass-ceramics exhibit higher E,due to the more uniformly dispersed amorphous phases and submicrocrystals/nanocrystals inside.How to effectively combine the advantages of both relaxor ferroelectric ceramics and glass-ceramics is of great significance for the development of new dielectric materials with high energy storage performance.In this work,we firstly prepared BaO-SrO-Bi_(2)O_(3)-Na_(2)0-TiO_(2)-Al_(2)O_(3)-SiO_(2)(abbreviated as GS)glass powders,and then fabricated(Ba_(0.3)Sr_(0.7))_(0.5)(Bi_(0.5)Na_(0.5))_(0.5)TiO_(3)+x wt%GS ceramic composites(abbreviated as BSo.sBNT-xGS,x=0,2,6,10,14,16,and 18).Submicrocrystals/nanocrystals with a similar composition to BSo.sBNT were crystalized from the glass,ensuring the formation of uniform core-shell structure in BSo.sBNT-xGS relaxor ferroelectric ceramic/glass-ceramic composites.When the addition amount of GS was 14 wt%,the composite possessed both high&r(>3200 at 1 kHz)and high E,(~170 kV/cm)at room temperature,and their recoverable energy storage density and efficiency were Wrec=2.1 J/cm’and n=65.2%,respectively.The BSo.sBNT-14GS composite also had several attractive properties such as good temperature,frequency,cycle stability,and fast charge-discharge speed.This work provides insights into the relaxor ceramic/glass-ceramic composites for pulsed power capacitors and sheds light on the utilization of the hybrid systems.
