随着我国科技水平的飞速发展，激光惯性导航系统的精度要求越来越高。采用工业级原材料，通过固相合成法制备了铌锑-铌镍-锆钛酸铅(PSN-PNN-PZT)四元系大应变压电陶瓷材料，讨论了不同含量Sr对PSN-PNN-PZT压电陶瓷材料介电性能、压电性能的影响。结果表明：当Sr含量为1%(摩尔分数)、n(Zr)/n(Ti)=43/57(摩尔比)时，PSN-PNN-PZT组成位于准同型相界附近，压电陶瓷性能较优，获得了一种相对介电常数εT33/ε0、机电耦合系数kp、压电常数d33、介电损耗tan δ、居里温度Tc分别为4 090、0.664、686 pC/N、0.016 5及213 ℃的大应变压电陶瓷材料；基于该材料配方制备的24 mm×5 mm×0.4 mm压电陶瓷圆环，在100 V的驱动电压下产生的应变量能达到2.500 5 μm，较现有的PZT-14(P14)材料提升32.4%，能应用于高精度激光陀螺稳频器中，提高压电陶瓷微位移驱动器的可靠性。

采用传统固相法制备了0.75Pb(Zr1/2Ti1/2)O3-xPb(Zn1/3Nb2/3)O3-(0.25-x)Pb(Ni1/3Nb2/3)O3 (0.75PZT-xPZN-(0.25-x)PNN,摩尔分数x=0.05, 0.10, 0.15, 0.20)压电陶瓷, 研究了x值对陶瓷晶体结构、烧结特性、微观组织和介电、铁电、压电性能的影响规律。结果表明, 陶瓷中三方相和四方相共存, 当x=0.10~0.20时, 陶瓷组分位于准同型相界(MPB)附近。随着PZN含量的增加, 三方相含量减少, 四方相含量增加, 陶瓷的介电常数(εT)、压电常数(d33)、机电耦合系数(kp)和能量转化因子(d33×g33)均随之先增大后减小, 当x=0.15时, 0.75PZT-0.15PZN-0.10PNN陶瓷具有最佳电学性能,即εT=1 850, 公电损耗tan δ=0.029, 居里温度TC=280 ℃, d33=370 pC/N, kp=0.67。

本文通过一步反应合成法制备了铌镁-锆钛酸铅(Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3, PMN-PZT)压电陶瓷, 研究了稀土元素钐(Sm)掺杂对PMN-PZT(x%(摩尔分数)Sm-PMN-PZT)结构与电学性能的影响规律, 得到了具有高压电性、高机电耦合系数和高居里温度的压电陶瓷。当x=2.0时, 压电常数d33=611 pC/N, 机电耦合系数kp=0.68, 介电损耗tan δ=1.65%,相对介电常数εr=2 650, 居里温度TC=283 ℃。测试压电陶瓷电致应变性能, 在3 kV/mm下单极电致应变达到0.20%, 显示出其大应变材料的特征。结果表明, Sm掺杂PMN-PZT压电陶瓷具有优异的综合电学性能, 有望在换能器、传感器以及致动器等领域广泛应用。

BiFeO3基无铅压电陶瓷常因漏电流较大而压电性能欠佳, 然而, 改善其绝缘性和电性能的方法都较为复杂, 限制了其产业化生产与应用。本工作在不针对0.7BiFeO3-0.3BaTiO3陶瓷进行组分掺杂以及气氛烧结的条件下, 仅通过简单的原料预处理(改变Fe2O3原料的干燥时间)即实现了其高绝缘性与高压电性能。研究结果表明,0.7BiFeO3-0.3BaTiO3陶瓷的晶粒尺寸和绝缘性随Fe2O3原料干燥时间的增加而增大, 同时其电性能及温度稳定性也随之增强。当原料干燥时间为192 h时, 样品晶粒尺寸最大, 绝缘性最好, 同时其压电性能(d33=203 pC/N,kp=0.33)和居里温度(Tc=460 ℃)也达到最佳。这为今后BiFeO3基陶瓷压电性能的研究提供了一个新思路。

The article presents the results of research the pre-transitional features of the behavior of solid solutions based on lead zirconate-titanate. The presence of a “special” critical temperature Td on the temperature dependences of the permittivity 𝜀(T) and the remanent polarization Pr(T), preceding the temperature of the paraelectric phase transition at the Curie temperature TC, is noted. In the temperature range T < Td, the Pr(T) dependence obeys a power law. In the temperature range Td<T<TC, this law is not fulfilled. The results of X-ray experiments make it possible to associate this behavior with reversible disordering at T<Td of an ordered domain structure formed during the polarization of piezoelectric ceramics and with its irreversible disordering in the temperature range Td<T<TC. This is due to the appearance of internal mechanical stresses in a polycrystalline ferroelectric due to irreversible depolarization of the samples at temperatures Td<T<TC.The article presents the results of research the pre-transitional features of the behavior of solid solutions based on lead zirconate-titanate. The presence of a “special” critical temperature Td on the temperature dependences of the permittivity 𝜀(T) and the remanent polarization Pr(T), preceding the temperature of the paraelectric phase transition at the Curie temperature TC, is noted. In the temperature range T < Td, the Pr(T) dependence obeys a power law. In the temperature range Td<T<TC, this law is not fulfilled. The results of X-ray experiments make it possible to associate this behavior with reversible disordering at T<Td of an ordered domain structure formed during the polarization of piezoelectric ceramics and with its irreversible disordering in the temperature range Td<T<TC. This is due to the appearance of internal mechanical stresses in a polycrystalline ferroelectric due to irreversible depolarization of the samples at temperatures Td<T<TC.

Ba0.85Ca0.15(Ti1−xZrx)O3(BCTZ) ceramics with x= 0.05, 0.10, 0.15, 0.20, 0.25, 0.30 were prepared by the solid-state reaction method. Calcination of the powders was carried out at 1100 ∘C for 4 h and the green pellets were sintered at 1400 ∘C for 2 h. X-ray diffraction patterns of the sintered pellets showed tetragonal splitting up to x= 0.10 while the mixture of the rhombohedral/cubic phase appeared at higher ZrO₂ concentrations. Maximum piezoelectric charge constant d33= 510 pC/N and strain (S= 0.103%) were measured for BCT doped by 0.10 mol ZrO₂. Dielectric constant, remnant polarization and saturation polarization also found maxima for this composition. The Curie temperature (TC) of the compositions decreased with increase in ZrO₂ concentration and reached 98 ∘C, 87 ∘C and 36 ∘C at x= 0.05, 0.10, 0.15 mol, respectively. The remaining compositions have TC below the room temperature; therefore, they can be used for subzero/cryogenic applications. The scanning electron microscopy study revealed an increase in grain size with increase in ZrO₂ concentration and confirmed the complete solubility of ZrO₂ in the crystal lattice. Overall, low ZrO₂-doped BCT compositions with high d33 could be suitable for low temperature (<80 ∘C) applications.Ba0.85Ca0.15(Ti1−xZrx)O3(BCTZ) ceramics with x= 0.05, 0.10, 0.15, 0.20, 0.25, 0.30 were prepared by the solid-state reaction method. Calcination of the powders was carried out at 1100 ∘C for 4 h and the green pellets were sintered at 1400 ∘C for 2 h. X-ray diffraction patterns of the sintered pellets showed tetragonal splitting up to x= 0.10 while the mixture of the rhombohedral/cubic phase appeared at higher ZrO₂ concentrations. Maximum piezoelectric charge constant d33= 510 pC/N and strain (S= 0.103%) were measured for BCT doped by 0.10 mol ZrO₂. Dielectric constant, remnant polarization and saturation polarization also found maxima for this composition. The Curie temperature (TC) of the compositions decreased with increase in ZrO₂ concentration and reached 98 ∘C, 87 ∘C and 36 ∘C at x= 0.05, 0.10, 0.15 mol, respectively. The remaining compositions have TC below the room temperature; therefore, they can be used for subzero/cryogenic applications. The scanning electron microscopy study revealed an increase in grain size with increase in ZrO₂ concentration and confirmed the complete solubility of ZrO₂ in the crystal lattice. Overall, low ZrO₂-doped BCT compositions with high d33 could be suitable for low temperature (<80 ∘C) applications.

The electrophysical and structural characteristics of bismuth titanate oxides of a number of phases of solid solutions of the Aurivillius phases Bi7−2xNd2xTi₄NbO21 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) having a layered structure of the perovskite type have been investigated. According to the XRD data, all studied compounds are single-phase and have a mixed-layer structure of Aurivillius phases (m = 2.5) with a rhombic crystal lattice (space group I2cm, Z = 2). A relationship has been established between changes in the chemical composition of solid solutions and orthorhombic and tetragonal distortions of perovskite-like layers. The temperature dependences of the relative permittivity 𝜀/𝜀o(T) are measured. It was found that the change in the phase transition temperature — Curie temperature TC synthesized Aurivillius phases Bi7−xNd2xTi₄NbO21 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) has a close to linear dependence on the change in the parameter x. The activation energies of charge carriers in different temperature ranges were calculated. It was found that three clearly defined temperature ranges with different activation energies can be distinguished, which is associated with the different nature of charge carriers in the studied solid solutions of the perovskite type. The effect of substitution of Nd3+ ions for Bi3+ ions is investigated.The electrophysical and structural characteristics of bismuth titanate oxides of a number of phases of solid solutions of the Aurivillius phases Bi7−2xNd2xTi₄NbO21 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) having a layered structure of the perovskite type have been investigated. According to the XRD data, all studied compounds are single-phase and have a mixed-layer structure of Aurivillius phases (m = 2.5) with a rhombic crystal lattice (space group I2cm, Z = 2). A relationship has been established between changes in the chemical composition of solid solutions and orthorhombic and tetragonal distortions of perovskite-like layers. The temperature dependences of the relative permittivity 𝜀/𝜀o(T) are measured. It was found that the change in the phase transition temperature — Curie temperature TC synthesized Aurivillius phases Bi7−xNd2xTi₄NbO21 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) has a close to linear dependence on the change in the parameter x. The activation energies of charge carriers in different temperature ranges were calculated. It was found that three clearly defined temperature ranges with different activation energies can be distinguished, which is associated with the different nature of charge carriers in the studied solid solutions of the perovskite type. The effect of substitution of Nd3+ ions for Bi3+ ions is investigated.

The Aurivillius phases [Bi₂O₂][An−1BnO3n+1] are well-known ferroelectrics with high Curie temperatures TC. High-temperature piezoceramics Bi3−xGdxTiTaO₉ (BGdTTa, x= 0.0, 0.1, 0.2, 0.3) were prepared by a solid-state reaction method. The structural and electrophysical characteristics of BGdTTa ceramics have been studied. According to the data of powder X-ray diffraction, all the compounds are single-phase with the structures of two-layer Aurivillius phases (m = 2) with the orthorhombic crystal lattice (space group A2₁am). The temperature dependence of the relative permittivity 𝜀/𝜀0 (T) of the compounds was measured and showed that the Curie temperature TC of perovskite-like oxides Bi3−xGdxTiTaO₉ increases linearly with an increase in the substitution parameter x to TC = 925∘C. The activation energies of charge carriers have been found in different temperature ranges.The Aurivillius phases [Bi₂O₂][An−1BnO3n+1] are well-known ferroelectrics with high Curie temperatures TC. High-temperature piezoceramics Bi3−xGdxTiTaO₉ (BGdTTa, x= 0.0, 0.1, 0.2, 0.3) were prepared by a solid-state reaction method. The structural and electrophysical characteristics of BGdTTa ceramics have been studied. According to the data of powder X-ray diffraction, all the compounds are single-phase with the structures of two-layer Aurivillius phases (m = 2) with the orthorhombic crystal lattice (space group A2₁am). The temperature dependence of the relative permittivity 𝜀/𝜀0 (T) of the compounds was measured and showed that the Curie temperature TC of perovskite-like oxides Bi3−xGdxTiTaO₉ increases linearly with an increase in the substitution parameter x to TC = 925∘C. The activation energies of charge carriers have been found in different temperature ranges.

该文采用传统固态反应法制备了Ca1-x(Li0.5Ce0.4Pr0.1)xBi2Ta2O9(x为摩尔分数)陶瓷, 研究了(Li0.5Ce0.4Pr0.1)2+复合离子不同掺杂浓度对陶瓷结构和电学性质的影响。结果表明, 在选定浓度范围内, (Li0.5Ce0.4Pr0.1)2+复合离子改善了CaBi2Ta2O9基陶瓷的压电活性与高温下的直流电阻等特性。当x=0.08时, 陶瓷具有最佳综合性能, 即压电常数d33=10.3 pC/N, 居里温度TC=928 ℃, 直流电阻率ρ=1.12×106 Ω·cm(650 ℃), 介电损耗tan δ=0.026(1 MHz,650 ℃)。