基于Swartz and Shrout的二次合成法,采用改进的两步法,将部分原料预合成,一次烧结合成具有100%钙钛矿结构的75Pb(Zn_(1/3)Nb_(2/3))O_3-10PbTiO_3-15BaTiO_3固溶体陶瓷。首先一次性称量PbO,然后和ZnNb_2O_6混合,在660～800℃预合成,将...基于Swartz and Shrout的二次合成法,采用改进的两步法,将部分原料预合成,一次烧结合成具有100%钙钛矿结构的75Pb(Zn_(1/3)Nb_(2/3))O_3-10PbTiO_3-15BaTiO_3固溶体陶瓷。首先一次性称量PbO,然后和ZnNb_2O_6混合,在660～800℃预合成,将预合成产物粉碎后再与TiO_2和BaCO_3按化学计量称量,充分混合后,在1060～1140℃保温1～2h烧结成陶瓷试样。实验结果表明:改进的两步法工艺能够将预合成温度降为660℃,烧结温度能被拓宽到80℃获得100%钙钛矿结构的固溶体陶瓷。不同于传统的预合成和烧结,改进的两步法工艺简单、有效,在预合成阶段没有形成钙钛矿相,烧结阶段陶瓷的成瓷和致密化同时进行,完成了中间相向钙钛矿相的转变,获得了介电性能优良的陶瓷试样。展开更多
利用室温下弛豫铁电单晶0.93Pb(Zn1/3Nb2/3)O3-0.07PbTiO3的材料参数,计算了[001]c极化PZN-7%PT晶体中的声表面波传播特性。结果表明,[001]c极化0.93Pb(Zn1/3Nb2/3)O3-0.07Pb TiO3单晶具有明显优于传统压电材料的声表面波特性。0.93Pb(Z...利用室温下弛豫铁电单晶0.93Pb(Zn1/3Nb2/3)O3-0.07PbTiO3的材料参数,计算了[001]c极化PZN-7%PT晶体中的声表面波传播特性。结果表明,[001]c极化0.93Pb(Zn1/3Nb2/3)O3-0.07Pb TiO3单晶具有明显优于传统压电材料的声表面波特性。0.93Pb(Zn1/3Nb2/3)O3-0.07Pb Ti O3单晶的声表面波特性随着传播方向发生明显的变化。综合考虑晶体的三种声表面波特性,发现Y切型晶体的综合声表面波性能最好,声表面波机电耦合系数k2值较大,能流角和声表面波自由表面相速度值较小,有望应用于下一代低频声表面波设备中。展开更多
Dipolar relaxation and dielectric/piezoelectric resonance in a (001)-cut Pb(Zn1/3Nb2/3)0.9Ti0.1O3 (PZNT10%) single crystal before and after electric (E)-field poling were presented. Dielectric permittivities were meas...Dipolar relaxation and dielectric/piezoelectric resonance in a (001)-cut Pb(Zn1/3Nb2/3)0.9Ti0.1O3 (PZNT10%) single crystal before and after electric (E)-field poling were presented. Dielectric permittivities were measured as functions of temperature, frequency and poling E-field strength. Frequency-dependent dielectric spectroscopy in the poled sample exhibits multiple piezoelectric resonances between 0.1 and 1 MHz, which can be described by the forced-damped-oscillator model. The resonant spectra show significant changes while phase transitions are taking place. The unpoled crystal shows almost no optical birefringence, indicating that the average structure symmetry is isotropic. Birefringence of the crystal is significantly enhanced by a prior E-field poling.展开更多
文摘基于Swartz and Shrout的二次合成法,采用改进的两步法,将部分原料预合成,一次烧结合成具有100%钙钛矿结构的75Pb(Zn_(1/3)Nb_(2/3))O_3-10PbTiO_3-15BaTiO_3固溶体陶瓷。首先一次性称量PbO,然后和ZnNb_2O_6混合,在660～800℃预合成,将预合成产物粉碎后再与TiO_2和BaCO_3按化学计量称量,充分混合后,在1060～1140℃保温1～2h烧结成陶瓷试样。实验结果表明:改进的两步法工艺能够将预合成温度降为660℃,烧结温度能被拓宽到80℃获得100%钙钛矿结构的固溶体陶瓷。不同于传统的预合成和烧结,改进的两步法工艺简单、有效,在预合成阶段没有形成钙钛矿相,烧结阶段陶瓷的成瓷和致密化同时进行,完成了中间相向钙钛矿相的转变,获得了介电性能优良的陶瓷试样。
文摘利用室温下弛豫铁电单晶0.93Pb(Zn1/3Nb2/3)O3-0.07PbTiO3的材料参数,计算了[001]c极化PZN-7%PT晶体中的声表面波传播特性。结果表明,[001]c极化0.93Pb(Zn1/3Nb2/3)O3-0.07Pb TiO3单晶具有明显优于传统压电材料的声表面波特性。0.93Pb(Zn1/3Nb2/3)O3-0.07Pb Ti O3单晶的声表面波特性随着传播方向发生明显的变化。综合考虑晶体的三种声表面波特性,发现Y切型晶体的综合声表面波性能最好,声表面波机电耦合系数k2值较大,能流角和声表面波自由表面相速度值较小,有望应用于下一代低频声表面波设备中。
文摘Dipolar relaxation and dielectric/piezoelectric resonance in a (001)-cut Pb(Zn1/3Nb2/3)0.9Ti0.1O3 (PZNT10%) single crystal before and after electric (E)-field poling were presented. Dielectric permittivities were measured as functions of temperature, frequency and poling E-field strength. Frequency-dependent dielectric spectroscopy in the poled sample exhibits multiple piezoelectric resonances between 0.1 and 1 MHz, which can be described by the forced-damped-oscillator model. The resonant spectra show significant changes while phase transitions are taking place. The unpoled crystal shows almost no optical birefringence, indicating that the average structure symmetry is isotropic. Birefringence of the crystal is significantly enhanced by a prior E-field poling.
