The ac impedance of Nb-doped semicon-ducting (Bao.72Pbo.28)TiO3 ceramics implanted with copper ions(200keV,6X1015 and 1X1017 ions/cm2) in the temperature range 25-320C and the frequency range 10 Hz -13MHz was measured...The ac impedance of Nb-doped semicon-ducting (Bao.72Pbo.28)TiO3 ceramics implanted with copper ions(200keV,6X1015 and 1X1017 ions/cm2) in the temperature range 25-320C and the frequency range 10 Hz -13MHz was measured. According to the change of impedance spectroscopy and the equivalent circuit model of semiconducting(Ba, Pb)TiO3 ceramics, the dependence of resistance of bulk and grain-boundary on temperature was analyzed. The results show that relatively low dose must be used to increase the magnitude of the positive temperature coeffieient of resistance(PTCR)effects in the cermmics. In addition,the effects of Cu ion implantation on the PTCR behavior of the ceramics was studied by raststance-tempera-ture measurement.展开更多
Pb(Mg_(1/3)Nb_(2/3))O_(3)–PbTiO_(3)(PMN-PT)piezoelectric ceramics have excellent piezoelectric properties and are used in a wide range of applications.Adjusting the solid solution ratios of PMN/PT and different conce...Pb(Mg_(1/3)Nb_(2/3))O_(3)–PbTiO_(3)(PMN-PT)piezoelectric ceramics have excellent piezoelectric properties and are used in a wide range of applications.Adjusting the solid solution ratios of PMN/PT and different concentrations of elemental doping are the main methods to modulate their piezoelectric coefficients.The combination of these controllable conditions leads to an exponential increase of possible compositions in ceramics,which makes it not easy to extend the sample data by additional experimental or theoretical calculations.In this paper,a physics-embedded machine learning method is proposed to overcome the difficulties in obtaining piezoelectric coefficients and Curie temperatures of Sm-doped PMN-PT ceramics with different components.In contrast to all-data-driven model,physics-embedded machine learning is able to learn nonlinear variation rules based on small datasets through potential correlation between ferroelectric properties.Based on the model outputs,the positions of morphotropic phase boundary(MPB)with different Sm doping amounts are explored.We also find the components with the best piezoelectric property and comprehensive performance.Moreover,we set up a database according to the obtained results,through which we can quickly find the optimal components of Sm-doped PMN-PT ceramics according to our specific needs.展开更多
The purpose of this research is to study the effect of thermal conditions such as temperature ramp rate and isothermal times in the phase formation of Pb(Zr1-xTix)O3 solid solutions with composition near the morphotro...The purpose of this research is to study the effect of thermal conditions such as temperature ramp rate and isothermal times in the phase formation of Pb(Zr1-xTix)O3 solid solutions with composition near the morphotropic phase boundary (MPB) by using the conventional ceramic method. The perovskite phase formation and morphology of undoped Pb(Zr0.52Ti0.48)O3 (abbreviated PZT) and doped new material Pb0.98Gd0.02[(Zr0.52Ti0.48)0.98(Mg1/3Nb2/3)0.01(Ni1/3Sb2/3)0.01]O3 (abbreviated PZT-PGMNNS) specimens calcined between 700°C and 900°C have been examined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) while the thermal evolution of the initial precursor was followed by TG-DTA. So the results of these studies have been discussed.展开更多
Recently,high-performance lead zirconate titanate(Pb(Zr_(1-x)Ti_(x))O_(3),PZT)ferroelectric ceramics have attracted intensive attention due to their wider operating temperature range,better temperature stability,as we...Recently,high-performance lead zirconate titanate(Pb(Zr_(1-x)Ti_(x))O_(3),PZT)ferroelectric ceramics have attracted intensive attention due to their wider operating temperature range,better temperature stability,as well as larger piezoelectric properties and higher energy conversion efficiency.In this study,the perovskite-type ferroelectric ceramics with a chemical formula of Pb_(0.99-x)Gd_(0.01)Sr_(x)Zr_(0.53)Ti_(0.47)O_(3)(x=0 and 0.02,abbr.PGZT and PGSZT,respectively)were prepared by the traditional solid-state reaction route.The influences of Sr-doping on the phase structure,dielectric properties,ferroelectric properties and piezoelectric properties of the PGZT ceramics were comprehensively investigated.The field-dependent P–E hysteresis loops of PGSZT were measured in the frequency range of 0.05–10 Hz and temperature range of 20–100℃.The results show that Sr-doping not only enhances the dielectric permittivity and piezoelectric coefficient of PGZT,but also decreases its dielectric loss tangent,with the d_(33) value of 473 pC/N,ε_(r) value of 1586 and tanδvalue of 0.016 found in PGSZT.Also,PGSZT shows a high Curie temperature(T_(C))of 350℃.The underlying mechanisms of the property enhancement were identified as that the introduced Sr^(2+) replaces the volatile Pb^(2+) located at the A-site of the perovskite structure,thereby reducing the concentration of lead vacancies and promoting the grain growth of the ceramics,consequently enhancing the dielectric and piezoelectric properties of PGZT.On the other hand,the frequency change in the low-frequency range(<1 Hz)played a significant impact on the remanent polarization(P_(r))and internal biased electric field(E_(i))of PGSZT,but the frequency dependence of coercive field(E_(c))tends to diminish in the high-frequency range(≥1 Hz).展开更多
Lead-free piezoelectric ceramics of (Bi1/2Na1/2)TiO3-BaTiO3(BNT-BT) were prepared by the conventional piezoelectric ceramic preparation technique (free air atmosphere sintering). The influence of BaTiO3 additive amoun...Lead-free piezoelectric ceramics of (Bi1/2Na1/2)TiO3-BaTiO3(BNT-BT) were prepared by the conventional piezoelectric ceramic preparation technique (free air atmosphere sintering). The influence of BaTiO3 additive amount and La2O3 additive amount on the properties of BNT-BT lead-free piezoceramics were investigated. The results show that the dielectric constant(ε) and piezoelectric strain constant(d33) of materials start increasing and then decreasing while BaTiO3 additive amount increasing, the e and d33 of materials have maximum value (ε= 1650, d33 = 120 PC·N -1 ) while x (BaTiO3) =0.06 mol. Theεand d33 of materials start increasing and then decreasing while La2O3 additive amount increasing, the e and d33 of materials have maximum value (ε= 1684, d33 = 153 PC·N-1) while w(La2O3) =0.3% . The influence of La2O3 additive amount on the microstructure of BNT-BT piezoelectric ceramics was analysed by SEM( scanning electron microscope). The influence mechanism of La2O3 additive amount on the properties of BNT-BT piezoelectric ceramics was discussed. The BNT-BT ceramics with optimum comprehensive properties were obtained.展开更多
文摘The ac impedance of Nb-doped semicon-ducting (Bao.72Pbo.28)TiO3 ceramics implanted with copper ions(200keV,6X1015 and 1X1017 ions/cm2) in the temperature range 25-320C and the frequency range 10 Hz -13MHz was measured. According to the change of impedance spectroscopy and the equivalent circuit model of semiconducting(Ba, Pb)TiO3 ceramics, the dependence of resistance of bulk and grain-boundary on temperature was analyzed. The results show that relatively low dose must be used to increase the magnitude of the positive temperature coeffieient of resistance(PTCR)effects in the cermmics. In addition,the effects of Cu ion implantation on the PTCR behavior of the ceramics was studied by raststance-tempera-ture measurement.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.52272116 and 12002400)the Natural Science Foundation of Shandong Province (Grant No.ZR2021ME096)the Youth Innovation Team Project of Shandong Provincial Education Department (Grant No.2019KJJ012)。
文摘Pb(Mg_(1/3)Nb_(2/3))O_(3)–PbTiO_(3)(PMN-PT)piezoelectric ceramics have excellent piezoelectric properties and are used in a wide range of applications.Adjusting the solid solution ratios of PMN/PT and different concentrations of elemental doping are the main methods to modulate their piezoelectric coefficients.The combination of these controllable conditions leads to an exponential increase of possible compositions in ceramics,which makes it not easy to extend the sample data by additional experimental or theoretical calculations.In this paper,a physics-embedded machine learning method is proposed to overcome the difficulties in obtaining piezoelectric coefficients and Curie temperatures of Sm-doped PMN-PT ceramics with different components.In contrast to all-data-driven model,physics-embedded machine learning is able to learn nonlinear variation rules based on small datasets through potential correlation between ferroelectric properties.Based on the model outputs,the positions of morphotropic phase boundary(MPB)with different Sm doping amounts are explored.We also find the components with the best piezoelectric property and comprehensive performance.Moreover,we set up a database according to the obtained results,through which we can quickly find the optimal components of Sm-doped PMN-PT ceramics according to our specific needs.
文摘The purpose of this research is to study the effect of thermal conditions such as temperature ramp rate and isothermal times in the phase formation of Pb(Zr1-xTix)O3 solid solutions with composition near the morphotropic phase boundary (MPB) by using the conventional ceramic method. The perovskite phase formation and morphology of undoped Pb(Zr0.52Ti0.48)O3 (abbreviated PZT) and doped new material Pb0.98Gd0.02[(Zr0.52Ti0.48)0.98(Mg1/3Nb2/3)0.01(Ni1/3Sb2/3)0.01]O3 (abbreviated PZT-PGMNNS) specimens calcined between 700°C and 900°C have been examined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) while the thermal evolution of the initial precursor was followed by TG-DTA. So the results of these studies have been discussed.
基金funded by the Natural Science Foundation of Sichuan Province(Grant No.2024NSFSC0219).
文摘Recently,high-performance lead zirconate titanate(Pb(Zr_(1-x)Ti_(x))O_(3),PZT)ferroelectric ceramics have attracted intensive attention due to their wider operating temperature range,better temperature stability,as well as larger piezoelectric properties and higher energy conversion efficiency.In this study,the perovskite-type ferroelectric ceramics with a chemical formula of Pb_(0.99-x)Gd_(0.01)Sr_(x)Zr_(0.53)Ti_(0.47)O_(3)(x=0 and 0.02,abbr.PGZT and PGSZT,respectively)were prepared by the traditional solid-state reaction route.The influences of Sr-doping on the phase structure,dielectric properties,ferroelectric properties and piezoelectric properties of the PGZT ceramics were comprehensively investigated.The field-dependent P–E hysteresis loops of PGSZT were measured in the frequency range of 0.05–10 Hz and temperature range of 20–100℃.The results show that Sr-doping not only enhances the dielectric permittivity and piezoelectric coefficient of PGZT,but also decreases its dielectric loss tangent,with the d_(33) value of 473 pC/N,ε_(r) value of 1586 and tanδvalue of 0.016 found in PGSZT.Also,PGSZT shows a high Curie temperature(T_(C))of 350℃.The underlying mechanisms of the property enhancement were identified as that the introduced Sr^(2+) replaces the volatile Pb^(2+) located at the A-site of the perovskite structure,thereby reducing the concentration of lead vacancies and promoting the grain growth of the ceramics,consequently enhancing the dielectric and piezoelectric properties of PGZT.On the other hand,the frequency change in the low-frequency range(<1 Hz)played a significant impact on the remanent polarization(P_(r))and internal biased electric field(E_(i))of PGSZT,but the frequency dependence of coercive field(E_(c))tends to diminish in the high-frequency range(≥1 Hz).
文摘Lead-free piezoelectric ceramics of (Bi1/2Na1/2)TiO3-BaTiO3(BNT-BT) were prepared by the conventional piezoelectric ceramic preparation technique (free air atmosphere sintering). The influence of BaTiO3 additive amount and La2O3 additive amount on the properties of BNT-BT lead-free piezoceramics were investigated. The results show that the dielectric constant(ε) and piezoelectric strain constant(d33) of materials start increasing and then decreasing while BaTiO3 additive amount increasing, the e and d33 of materials have maximum value (ε= 1650, d33 = 120 PC·N -1 ) while x (BaTiO3) =0.06 mol. Theεand d33 of materials start increasing and then decreasing while La2O3 additive amount increasing, the e and d33 of materials have maximum value (ε= 1684, d33 = 153 PC·N-1) while w(La2O3) =0.3% . The influence of La2O3 additive amount on the microstructure of BNT-BT piezoelectric ceramics was analysed by SEM( scanning electron microscope). The influence mechanism of La2O3 additive amount on the properties of BNT-BT piezoelectric ceramics was discussed. The BNT-BT ceramics with optimum comprehensive properties were obtained.
