共查询到19条相似文献,搜索用时 462 毫秒
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反铁电陶瓷材料在电场诱导下发生反铁电-铁电相变.为了研究快速电场诱导相变,诱导电场选择高压脉冲电源产生的脉冲电场.反铁电陶瓷选用Pb(Zr,Sn,Ti)O3相图中位于反铁电-铁电相界附近,正向相变电场小于40kV/cm的锆锡钛酸铅.脉冲电源输出波形为2.7 μs电压脉冲,测量陶瓷样品两端的电压波形与所通过的电流波形,作出正向半周期的"脉冲电滞回线".可以看到反铁电陶瓷在脉冲电场诱导下发生了相变. 相似文献
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研究了掺铌PZST反铁电陶瓷中组份和温度对诱导反铁电-铁电相变转换电场的影响,测定了Pb0.99Nb0.02((Zr0.80Sn0.20)1-yTiy)0.98O3系中正向转换电场EF与组份y(Ti)的关系和电极化前后的反铁电/铁电相界。实验测量结果显示,某组份y(Ti)的反映电-铁电转换强度大小取决于该组份与铁电/铁电相界组份的差距。在Pb0.99Nb0.02((Zr0.80Sn0.20)1-yTiy)0.98O3系中随着试样温度升高,反向转换电场EB保持不变,正向转换电场EF和电滞△E降低。这一现象表明温度有助于降低反铁电-铁电相变的应能使得电场诱导反铁电-铁电相变容易进行,因此可以采用加热电极化方法来降低极化电场强度。 相似文献
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仔细研究了电场感应PbZrO3铁电相的晶体结构。在PbZrO3处于反铁电相时,各离子位移方向与极轴垂直。在外电场感应下,Pb离子沿极轴方向有相同方向0.17A的位移,从而使晶体呈现铁电相特征,发生反铁电-铁电相变。此铁电相称之为电场感应铁电相(EFI,Electric—Field—Induced)。通过结构对称性分析,确定EFI铁电相的对称性是C2mm(G2v),用极矢量Ps作为序参量来描述相变时对称性的变化是合适的。 相似文献
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反铁电材料在发生场致反铁电-铁电相变过程中伴随着巨大应变和能量的储存和释放,故在高密度储能器件和机电换能器上极具应用潜力。综述了具有钙钛矿结构的Pb基反铁电体结构特点与性能调控,特别是Pb(Zr,Ti)O3(PZT)基反铁电储能材料的研究进展与存在问题。重点讨论了几类典型元素掺杂Pb基反铁电薄膜材料研究的最新进展。简要介绍了适应无铅化要求、环境友好的无铅钙钛矿型反铁电-铁电相变材料。最后对当前钙钛矿型Pb基反铁电材料研究与应用中尚需深入探究的问题进行了总结。 相似文献
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采用快速退火工艺在Pt/Ti/SiO2/p-Si衬底上制备了Bi4Ti3O12铁电薄膜.研究了退火温度对薄膜微观结构、铁电特性及介电性能的影响.研究表明:退火温度对Si基Bi4Ti3O12铁电薄膜晶相结构的影响显著,对晶粒尺寸和表面形貌的影响较小,但退火温度超过800℃后会出现焦绿石等杂相;低于750℃时,薄膜的剩余极化随退火温度升高而增大,高于750℃时却有所减小,但矫顽电场随退火温度升高而逐渐降低;退火温度对薄膜的漏电流密度有一定的影响,薄膜的漏电流密度在200kV/cm极化电场作用下低于3×10-9A/cm2,750℃时的剩余极化和矫顽电场分别为11μC/cm2和77kV/cm,具有较好的铁电和介电性能. 相似文献
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漏电流是铁电薄膜应用过程中的关键问题。本文通过磁控溅射法制备了结晶性能良好的铌镁锆钛酸铅(PZT-PMN)铁电薄膜,并在室温下用原子氧对其进行处理,研究了原子氧对PZT-PMN薄膜表层微观结构和漏电流的影响。实验结果表明:经原子氧处理后的PZT-PMN薄膜,①表面粗糙度下降且有非晶层形成;②表层有大量的氧原子进入;③漏电流密度减小了大约一个数量级,外加电压为2.5 V时,未处理样品的漏电流密度为3×10-5A/cm2,处理样品的漏电流密度降为4.5×10-6A/cm2。原子氧对PZT-PMN薄膜内部晶界、缺陷的钝化是薄膜漏电流减小的原因。 相似文献
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Xiujian Chou Wenping Geng Yongbo Lv Jun Liu Wendong Zhang 《Journal of Materials Science: Materials in Electronics》2013,24(3):861-865
(Pb,La)(Zr,Ti)O3 antiferroelectric 1.4 μm-thick films have been prepared on Pt (111)/Ti/SiO2/Si(100) substrates by sol–gel process. The structures and dielectric properties of the antiferroelectric thick films were investigated. The films displayed pure perovskite structure with (100)-preferred orientation. The surface of the films was smooth, compact and uniform. The antiferroelectric (AFE) characterization have been demonstrated by P (polarization)-E (electric field) and C(capacitance)-V (DC bias) curves. The AFE–ferroelectric (FE) and FE-to-paraelectric (PE) phase transition were also investigated as coupling functions of temperature and direct current electric field. With the applied field increased, the temperature of AFE-to-FE phase transition decreased and the FE-to-PE phase shifted to high temperature. The AFE-to-FE phase transition was adjustable by direct current electric field. (Pb,La) (Zr,Ti) O3 antiferroelectric films have broad application prospects in microelectromechanical systems because of the phase transition. 相似文献
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Ferroelectric/antiferroelectric bi-layer ceramics with different ferroelectric and antiferroelectric phase thickness ratio (FE/AFE thickness ratio) in Pb(Nb, Zr, Sn, Ti)O3 system were prepared and characterized. With increasing the maximum external electric field from 0 to 40 kV/cm, polarization-electric field relation was always ferroelectric-like or underwent an antiferroelectric-ferroelectric transition, depending on the FE/AFE thickness ratio. All layered ceramics showed ferroelectric-like hysteresis loops with maximum external electric field of 40 kV/cm, and much higher remanent polarizations were attained than those of the ferroelectric/antiferroelectric heterostructures reported previously. 相似文献
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Baomin Xu Yaohong Ye Qing-Ming Wang N. G. Pai L. E. Cross 《Journal of Materials Science》2000,35(23):6027-6033
The composition-dependent electrical properties in (Pb,La)(Zr,Ti,Sn)O3 antiferroelectric-ferroelectric phase switching thin and thick films have been systematically studied and compared with bulk ceramics. The films were deposited on Pt-buffered silicon substrates by a sol-gel method. The results show that the dependence of low-field dielectric properties on compositions in the films is similar to that in bulk ceramics but the variation of high field properties (polarization or hysteresis loops) is quite different, which may be attributed to the special mechanical boundary condition of the films. While all the films with compositions in the antiferroelectric tetragonal region in the phase diagram demonstrate the existence of remanent polarization in the hysteresis loops, the films with zero remanent polarization can be obtained in the antiferroelectric orthorhombic region. This is because the films are under high tensile stress due to the thermal mismatch between the film and substrate, which tends to stabilize the ferroelectric phase and causes the retention of ferroelectric phase for the films in the antiferroelectric tetragonal region because of their relatively small free energy difference between the antiferroelectric phase and ferroelectric phase. 相似文献
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Yoshihisa Honda Shintaro Yokoyama Hiroshi Funakubo Keisuke Saito 《Materials Science and Engineering: B》2005,120(1-3):161-165
Two micrometers thick (Pb, La)(Zr, Ti)O3 [PLZT] films with wide composition range were epitaxially grown on (1 0 0)SrRuO3 bottom electrode layers epitaxially grown (1 0 0) SrTiO3 substrates by metal organic chemical vapor deposition. Constituent phase of the films were found to be almost the same with the reported phase diagram for the sintered body except for the wider coexistence region of tetragonal and rhombohedral phases. The change of the measured field-induced strain with the electric field was almost respond to the square of the polarization of the films except the negative strain region, but the magnitude was different. This is due to the increase of the electrostatic coefficient of the film with increasing the La/(Pb + La) ratio. As a results, field induced strain of the PLZT film was found to be controlled by adjusting the composition of PLZT films. 相似文献
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The relaxor antiferroelectric (Pb,La)(Zr,Sn,Ti)O3 powders were synthesized by conventional mixed oxide method and coprecipitation method. The XRD patterns show that pure perovskite
phase formation temperature was 700 °C for the coprecipitation method and that was 1,100 °C for the conventional mixed oxide
method. Effect of the methods on sintering behavior and microstructures of the ceramics has been investigated by SEM. Both
the samples exhibit typical antiferroelectric double hysteresis loops with maximum polarization of 18.2 μC/cm2, forward-switching field of 6.2 kV/mm by conventional mixed oxide method, and 33.1 μC/cm2, 4.3 kV/mm by coprecipitation method, respectively. 相似文献
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The (Pb,Nb)(Zr,Sn,Ti)O3 (PNZST) antiferroelectric thin films were prepared on two different substrates by sol-gel methods. Films derived on the LNO/Pt/Ti/SiO2/Si substrates showed a strong (100) preferred orientation. The dependence of electrical properties derived on the Pt/Ti/SiO2/Si and LNO/Pt/Ti/SiO2/Si substrates have been studied, with the emphasis placed on field-induced phase switching from the antiferroectric to the ferroelectric state. The PNZST thin films deposition on two kinds of substrates show different phase transition behavior and associated properties such as antiferroelectric (AFE) to ferrroelectric (FE) switching field EAFE-FE, FE to AFE switching field EFE-AFE and the hysteresis ΔE=EAFE-FE−EFE-AFE. 相似文献
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Zhu BP Guo WK Shen GZ Zhou Q Shung KK 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(9):1962-1967
Ternary lead magnesium niobate-lead zirconate titanate system 0.4Pb(Mg(1/3)Nb(2/3))O(3)-0.25PbZrO(3)-0.35PbTiO(3) (40PMN-25PZ-35PT) thin film with a thickness of 1.5 μm was grown on Pt(111)/Ti/SiO(2)/Si substrate via chemical solution deposition. X-ray diffraction and transmission electron microscopy results suggested the film obtained was highly (111)-oriented. The remanent polarization and coercive electric field of the film were found to be 25.5 μC/cm(2) and 51 kV/cm, respectively. In addition, at 1 kHz, the dielectric constant was measured to be 1960 and the dielectric loss 0.036. The film was observed to undergo a diffuse ferroelectric-to-paraelectric phase transition at around 209°C. The leakage current appeared to depend on the voltage polarity. If the Au electrode was biased positively, the leakage current was dominated by the Schottky emission mechanism. When the Pt electrode was biased positively, the conduction current curve showed an ohmic behavior at a low electric field and space-charge-limited current characteristics at a high electric field. 相似文献
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The electrical properties of Pb(Zr, Ti)O3 thin films annealed by Pt thin film heater were investigated. By the thin film heater, we successfully crystallized Pb(Zr, Ti)O3 thin films at a high temperature above 750 °C in a few seconds. The thin film heater has some advantages, such as a low thermal budget, little Pb-loss and enhanced surface morphology compared with the conventional furnace because it has a fast heating rate. The electrical properties of the Pb(Zr, Ti)O3 thin film crystallized by thin film heater improved considerably comparing to those crystallized in conventional furnace. The remanent polarization, breakdown field, and leakage current density measured to be 22.7 μC/cm2, 853 kV/cm, and 6.93 × 10−7 A/cm2, respectively. 相似文献
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采用溶胶-凝胶法在Pt/Ti/SiO_2/Si(111)衬底上制备了Bi_(0.975)La_(0.025)Fe_(0.975)Ni_(0.025)O_3(BLFNO)铁电薄膜。利用X射线衍射(XRD)、原子力显微镜(AFM)及其压电模式(PFM)对薄膜的晶体结构、表面形貌以及铁电畴结构进行了研究。研究发现,BLFNO为结晶良好的钙钛矿结构多晶薄膜,且薄膜表面颗粒生长均匀。PFM测试图显示铁电薄膜在自发极化下的铁电畴结构清晰,铁电电容器具有良好的铁电性能。应用铁电测试仪对Pt/BLFNO/Pt电容器进行测量,得到了饱和性良好的电滞回线。在828kV/cm的外加电场下,Pt/BLFNO/Pt电容器的剩余极化强度为74.3μC/cm~2,表明La、Ni的共掺杂没有明显抑制铁电电容器的剩余极化强度,铁电电容器具有良好的铁电性能。漏电流研究结果表明,La、Ni元素的共掺杂有效降低了薄膜的漏电流密度,在277.8kV/cm外加电场下漏电流密度在10-4 A/cm2量级,明显小于纯BFO薄膜的漏电流密度。正半支漏电流曲线满足SCLC导电机制,对于负半支曲线,当电场强度大于22.2kV/cm时,同样遵循SCLC导电机制;但是,当电场强度小于22.2kV/cm时,曲线斜率约为4.8,表明参与导电贡献的电子数较多,归因于极浅陷阱俘获的电子在外加电场作用下参与了导电行为。室温下磁滞回线测试结果表明BLFNO薄膜具有反铁磁性质。 相似文献