The microstructures and electrical properties of Bi0.5（Na1-x-yKxLiy）0.5TiO3 lead-free piezoelectric ceramics were studied.These ceramics were prepared by conventional ceramic technique.XRD analysis reveals that the ...The microstructures and electrical properties of Bi0.5（Na1-x-yKxLiy）0.5TiO3 lead-free piezoelectric ceramics were studied.These ceramics were prepared by conventional ceramic technique.XRD analysis reveals that the ceramics possess almost pure perovskite phase when y≤0.2.The SEM results show that,with more amounts of Li＋,the crystalline grain growing speed is accelerated,and the sintering temperature can effectively be decreased.The measurements of piezoelectric properties indicate that the ceramics with relatively low amount of Li＋ and high amount of K＋ have comparatively large piezoelectricity.The dielectric measurements show that the ceramics have properties like relaxor ferroelectrics and diffuse phase transition（DPT） at Td and Tc,respectively.The results of ferroelectric measurements reveal the system has relatively higher remanent polarization Pr（27.6 μC/cm2） and lower coercive field Ec（37.5 kV/cm）.展开更多
Lead-free piezoelectric ceramics （1-y）Bi0.5（Na1-xLix）0.5TiO3-yBaTiO3 with x=0-0.125 and y=0.02-0.12 were fabricated by a solid-state reaction process, and their dielectric, piezoelectric and ferroelectric properti...Lead-free piezoelectric ceramics （1-y）Bi0.5（Na1-xLix）0.5TiO3-yBaTiO3 with x=0-0.125 and y=0.02-0.12 were fabricated by a solid-state reaction process, and their dielectric, piezoelectric and ferroelectric properties were investigated. The results show that the addition of Li^＋ significantly improves the sintering performance and piezoelectric properties of the ceramics. X-ray diffraction （XRD） patterns indicate that the ceramics possess pure perovskite structure. At room temperature, the ceramics provide high piezoelectric charge constant d33 （up to 210 pC/N）, high planar electromechanical coupling factor kp （34.5%）, large remanent polarization Pr （up to 40 μC/cm^2）, and low coercive field Ec （3.0 kV/mm）, which indicates that （1-y）Bi0.5（Na1-xLix）0.5TiO3-yBaTi03 is a good lead-free piezoelectric ceramic.展开更多
A new group of lead-free piezoelectric ceramics,（Bi0.5 Na0.5）1-x（BaaSrb）xTiO3（abbreviated as BNBST[100x-100a/100b],0〈x〈1,a＋b=1）,was synthesized.The ceramics were prepared by conventional ceramic sintering tec...A new group of lead-free piezoelectric ceramics,（Bi0.5 Na0.5）1-x（BaaSrb）xTiO3（abbreviated as BNBST[100x-100a/100b],0〈x〈1,a＋b=1）,was synthesized.The ceramics were prepared by conventional ceramic sintering technique,and the ceramics with density of 95% of the theoretical one can be sintered without the atmosphere control during the sintering process.The results of the X-ray diffraction（XRD） data show that the ceramics possess a single perovskite phase.The measurements of dielectric and piezoelectric properties reveal that the ceramics provide relatively high piezoelectric charge constant d33 and high planar electromechanical coupling factor kp.For the BNBST6-95/5 ceramics,d33 is equal to 170pC/N,and kp is equal to 32.0%.The fabrication technique for these ceramics is conventional and stable.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
基金Supported by Program for New Century Excellent Talents in University(No.NCET-07-0329)
文摘The microstructures and electrical properties of Bi0.5（Na1-x-yKxLiy）0.5TiO3 lead-free piezoelectric ceramics were studied.These ceramics were prepared by conventional ceramic technique.XRD analysis reveals that the ceramics possess almost pure perovskite phase when y≤0.2.The SEM results show that,with more amounts of Li＋,the crystalline grain growing speed is accelerated,and the sintering temperature can effectively be decreased.The measurements of piezoelectric properties indicate that the ceramics with relatively low amount of Li＋ and high amount of K＋ have comparatively large piezoelectricity.The dielectric measurements show that the ceramics have properties like relaxor ferroelectrics and diffuse phase transition（DPT） at Td and Tc,respectively.The results of ferroelectric measurements reveal the system has relatively higher remanent polarization Pr（27.6 μC/cm2） and lower coercive field Ec（37.5 kV/cm）.
基金supported by the National Nat-ural Science Foundation of China (No 50572066)the Sichuan Provincial Department of Education, China (No2006A075)the Doctor Start-up Foundation of China West Normal University (No 06B059)
文摘Lead-free piezoelectric ceramics （1-y）Bi0.5（Na1-xLix）0.5TiO3-yBaTiO3 with x=0-0.125 and y=0.02-0.12 were fabricated by a solid-state reaction process, and their dielectric, piezoelectric and ferroelectric properties were investigated. The results show that the addition of Li^＋ significantly improves the sintering performance and piezoelectric properties of the ceramics. X-ray diffraction （XRD） patterns indicate that the ceramics possess pure perovskite structure. At room temperature, the ceramics provide high piezoelectric charge constant d33 （up to 210 pC/N）, high planar electromechanical coupling factor kp （34.5%）, large remanent polarization Pr （up to 40 μC/cm^2）, and low coercive field Ec （3.0 kV/mm）, which indicates that （1-y）Bi0.5（Na1-xLix）0.5TiO3-yBaTi03 is a good lead-free piezoelectric ceramic.
文摘A new group of lead-free piezoelectric ceramics,（Bi0.5 Na0.5）1-x（BaaSrb）xTiO3（abbreviated as BNBST[100x-100a/100b],0〈x〈1,a＋b=1）,was synthesized.The ceramics were prepared by conventional ceramic sintering technique,and the ceramics with density of 95% of the theoretical one can be sintered without the atmosphere control during the sintering process.The results of the X-ray diffraction（XRD） data show that the ceramics possess a single perovskite phase.The measurements of dielectric and piezoelectric properties reveal that the ceramics provide relatively high piezoelectric charge constant d33 and high planar electromechanical coupling factor kp.For the BNBST6-95/5 ceramics,d33 is equal to 170pC/N,and kp is equal to 32.0%.The fabrication technique for these ceramics is conventional and stable.
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.
