The lead-free SrZrO3-modified Bi0.5Na0.5TiO3(BNT-SZ100 x, with x=0-0.15) ceramics were fabricated by a conventional solid-state reaction method. The effects of SZ addition on BNT ceramics were investigated through X-r...The lead-free SrZrO3-modified Bi0.5Na0.5TiO3(BNT-SZ100 x, with x=0-0.15) ceramics were fabricated by a conventional solid-state reaction method. The effects of SZ addition on BNT ceramics were investigated through X-ray diffraction(XRD), scanning electron microscopy(SEM), ferroelectric and electric field-induced strain characterizations. XRD analysis revealed a pure perovskite phase without any traces of secondary phases. Ferroelectric and bipolar field induced-strain curves indicated a disruption of ferroelectric order upon SZ addition into BNT ceramics. A maximum value of remnant polarization(32 μC/cm2) and piezoelectric constant(102 pC/N) was observed at 5%(mole fraction) of SZ. Maximum value of the electric field-induced strain(Smax=0.24%) corresponding to normalized strain(Smax/Emax= d*33= 340 pm/V) was obtained at BNT-SZ9.展开更多
The lead-free ceramics(1−x)(0.94Bi0.47Na0.47Ba0.06TiO3-0.06BiAlO3)-xAgNbO3(denoted as BNBTA-xAN)were synthesized via a solid-state sintering method.The effect of AgNbO3 doping amount on dielectric properties of the ce...The lead-free ceramics(1−x)(0.94Bi0.47Na0.47Ba0.06TiO3-0.06BiAlO3)-xAgNbO3(denoted as BNBTA-xAN)were synthesized via a solid-state sintering method.The effect of AgNbO3 doping amount on dielectric properties of the ceramics was studied systematically.X-ray diffraction(XRD),scanning electron microscope(SEM)and Raman spectroscope were used to detect the structure of the ceramics.Temperature-dependent dielectric spectra,frequency-dependent dielectric constant and alternating current(ac)electric conductance at various temperatures were measured.The doping of AgNbO3 greatly reduces dielectric constant around Curie temperature and thus enhances the temperature stability of the dielectric constant.The ceramic BNBTA-0.03AN exhibits excellent temperature-stable dielectric properties with temperature coefficient of capacitance(TCC)≤±15%between 55°C and 418°C with temperature window 363°C and small changes of dielectric constant and dielectric loss from 100 Hz to 1 MHz at different temperatures.The obtained ceramics are expected to be used in high-temperature capacitors due to its excellent temperature stability.展开更多
Multilayer ceramic actuator(MLCA)has been widely employed in actuators due to the large cumulative displacement under the low driving voltage.In this work,the MLCA devices consisting of a lead-free MnCO_(3-)and CuO-do...Multilayer ceramic actuator(MLCA)has been widely employed in actuators due to the large cumulative displacement under the low driving voltage.In this work,the MLCA devices consisting of a lead-free MnCO_(3-)and CuO-doped 0.96(K_(0.48)Na_(0.52))(Nb_(0.96)Ta_(0.04))O_(3)-0.04CaZrO_(3) piezoelectric ceramics and a base nickel(Ni)metal inner electrode were well co-fired by the two-step sintering process in a reducing atmosphere.The ceramic layer/electrode interface is well-integrated and clearly continuous without distinct interdiffusion and chemical reaction,which is beneficial to the electrical reliability of the MLCA.As a result,the MLCA laminated with nine active ceramic layers obtains an ultrahigh piezoelectric coefficient d_(33) of 3157 pC/N,about 9 times than bulk ceramics.The 0.5 mm-thick MLCA composed of a series of~50μm-thick ceramic layers and~3μm-thick Ni electrodes reaches a high 1.8μm displacement under the low applied voltage of 200 V(the same displacement requires a voltage as high as 3700 V for~1 mm-thick bulk ceramics).The excellent electrical performance and low-cost base electrode reveal that the(K,Na)NbO_(3)(KNN)-based MLCAs are promising lead-free candidate for actuator application.展开更多
The research on lead-free piezoelectric ceramics has been one of the importantfields worldwide for years for the sustainable development of the world.In recent years,the author and his group concentrated their work on...The research on lead-free piezoelectric ceramics has been one of the importantfields worldwide for years for the sustainable development of the world.In recent years,the author and his group concentrated their work on perovskite lead-free piezoelectric ceramics,especially on(Bi_(1/2)Na_(1/2))TiO_(3)(BNT)-and K_(1/2)Na_(1/2)NbO_(3)(KNN)-based ceramics.In this paper,the researches of the composition design on BNT-and KNN-based lead-free piezoelectric ceramics,the effects of doping on the properties of these ceramics,the study of the temperature stability of these ceramics,and the fabrication technique used in the author's group for these ceramics are reviewed,and the further considerations and some prospects to be resolved in coming years from the viewpoint of the device applications of these ceramics are suggested.展开更多
基金supported by the Basic Research program through the National Research Foundation of Korea (NRF) funded by Ministry, Science and Technology (MEST) (2011-0030058)
文摘The lead-free SrZrO3-modified Bi0.5Na0.5TiO3(BNT-SZ100 x, with x=0-0.15) ceramics were fabricated by a conventional solid-state reaction method. The effects of SZ addition on BNT ceramics were investigated through X-ray diffraction(XRD), scanning electron microscopy(SEM), ferroelectric and electric field-induced strain characterizations. XRD analysis revealed a pure perovskite phase without any traces of secondary phases. Ferroelectric and bipolar field induced-strain curves indicated a disruption of ferroelectric order upon SZ addition into BNT ceramics. A maximum value of remnant polarization(32 μC/cm2) and piezoelectric constant(102 pC/N) was observed at 5%(mole fraction) of SZ. Maximum value of the electric field-induced strain(Smax=0.24%) corresponding to normalized strain(Smax/Emax= d*33= 340 pm/V) was obtained at BNT-SZ9.
基金supported by the National Natural Science Foundation of China(Nos.52272118 and 51972202)Shaanxi Province Science and Technology Foundation(No.2022JM022).
文摘The lead-free ceramics(1−x)(0.94Bi0.47Na0.47Ba0.06TiO3-0.06BiAlO3)-xAgNbO3(denoted as BNBTA-xAN)were synthesized via a solid-state sintering method.The effect of AgNbO3 doping amount on dielectric properties of the ceramics was studied systematically.X-ray diffraction(XRD),scanning electron microscope(SEM)and Raman spectroscope were used to detect the structure of the ceramics.Temperature-dependent dielectric spectra,frequency-dependent dielectric constant and alternating current(ac)electric conductance at various temperatures were measured.The doping of AgNbO3 greatly reduces dielectric constant around Curie temperature and thus enhances the temperature stability of the dielectric constant.The ceramic BNBTA-0.03AN exhibits excellent temperature-stable dielectric properties with temperature coefficient of capacitance(TCC)≤±15%between 55°C and 418°C with temperature window 363°C and small changes of dielectric constant and dielectric loss from 100 Hz to 1 MHz at different temperatures.The obtained ceramics are expected to be used in high-temperature capacitors due to its excellent temperature stability.
基金supported by the National Natural Science Foundation of China(GrantNos.52072150 and 51972146)Shandong Province Key Fundamental Research Program(Grant No.ZR2022ZD39)+1 种基金State Key Laboratory of New Ceramics and Fine Processing,Tsinghua University(Grant No.KF202002)Open Foundation of Guangdong Key Laboratory of Electronic Functional Materials andDevices(Grant No.EFMD2021002Z).
文摘Multilayer ceramic actuator(MLCA)has been widely employed in actuators due to the large cumulative displacement under the low driving voltage.In this work,the MLCA devices consisting of a lead-free MnCO_(3-)and CuO-doped 0.96(K_(0.48)Na_(0.52))(Nb_(0.96)Ta_(0.04))O_(3)-0.04CaZrO_(3) piezoelectric ceramics and a base nickel(Ni)metal inner electrode were well co-fired by the two-step sintering process in a reducing atmosphere.The ceramic layer/electrode interface is well-integrated and clearly continuous without distinct interdiffusion and chemical reaction,which is beneficial to the electrical reliability of the MLCA.As a result,the MLCA laminated with nine active ceramic layers obtains an ultrahigh piezoelectric coefficient d_(33) of 3157 pC/N,about 9 times than bulk ceramics.The 0.5 mm-thick MLCA composed of a series of~50μm-thick ceramic layers and~3μm-thick Ni electrodes reaches a high 1.8μm displacement under the low applied voltage of 200 V(the same displacement requires a voltage as high as 3700 V for~1 mm-thick bulk ceramics).The excellent electrical performance and low-cost base electrode reveal that the(K,Na)NbO_(3)(KNN)-based MLCAs are promising lead-free candidate for actuator application.
基金This work was supported by National Science Foundation of China(NSFC Nos.59972020,50410179,50572066,50772068,and 50972095)Foundation of Doctor Training Programin University and College in China(Nos.20030610035 and 20080610020).The author thanks Mrs.Wu Wenjuan for her assistance in preparing the manuscript。
文摘The research on lead-free piezoelectric ceramics has been one of the importantfields worldwide for years for the sustainable development of the world.In recent years,the author and his group concentrated their work on perovskite lead-free piezoelectric ceramics,especially on(Bi_(1/2)Na_(1/2))TiO_(3)(BNT)-and K_(1/2)Na_(1/2)NbO_(3)(KNN)-based ceramics.In this paper,the researches of the composition design on BNT-and KNN-based lead-free piezoelectric ceramics,the effects of doping on the properties of these ceramics,the study of the temperature stability of these ceramics,and the fabrication technique used in the author's group for these ceramics are reviewed,and the further considerations and some prospects to be resolved in coming years from the viewpoint of the device applications of these ceramics are suggested.
