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81.
S. B. Majumder P. S. Dobal B. Roy S. Bhaskar R. S. Katiyar Amar Bhalla 《Ferroelectrics Letters Section》2001,28(3):85-92
We have studied the effect of rare earth dopants (Nd, Gd and Ce) on the phase formation behavior and electrical properties of sol-gel derived Pb1.05(Zr0.53Ti0.47)O3 thin films. In all these films the perovskite phase is obtained up to 5 at% doping and beyond that pyrochlore phase was found to coexist with the perovskite phase. Ce and Gd doping(1-2 at%) exhibited improved ferroelectric and dielectric properties as compared to the undoped PZT films. Nd doping (2 at%) was found to be effective to increase the retained switchable polarization of undoped PZT from 63% to 84%. The transition temperature of undoped PZT film was found to be reduced with Nd doping. The Nd doped films also exhibited typical relaxor behavior and a diffuse phase transition, characteristic of the relaxor material. Introduction of Nd into the PZT lattice probably introduces disorder in the B site of ABO3 lattice which causes the observed relaxor behavior 相似文献
82.
ABSTRACT A microelectromechanical systems-based handwriting system device was designed. We proposed an ominidirectional acoustical sensor microarray which can offer isotropic directional sensitivity with a high radiation acoustic power when it as a transmitter and a high array spatial gain (AG) when it as a receiver. It has been designed for use in the novel handwriting recognition system to attain a large writeable scale and to write in any direction. The proposed array device based on novel ferroelectric thin film has excellent performance, miniature size and high reliability, and could be fabricated with conventional integrated circuit process. 相似文献
83.
先给出了PbZr0.52Ti0.48O3(PZT)陶瓷材料在低温下变温XRD分析结果,证明了超晶格的出现与材料的微结构变化有关。测试了该样品在低温下的疲劳性能。与超晶格出现以前相比,其疲劳寿命有所提高,这对于PZT材料的应用有着重要的意义。 相似文献
84.
本文研究了水热条件下Bi3+、K+、OH-对水热合成PZT结晶粉末化学性质的影响,并用了XRD、EPMA和SEM及原子吸收光谱分析,对水热合成PZT结晶粉末及其烧结体进行了分析 相似文献
85.
Partial Discharge Signal Detection by Piezoelectric Ceramic Sensor and The Signal Processing 总被引:2,自引:0,他引:2
Kee-Joe Lim Seong-Hwa Kang Kang-Won Lee Sung-Hee Park Jong-Sub Lee 《Journal of Electroceramics》2004,13(1-3):487-492
Partial discharge (PD) in an insulator or on surface of defective conductor emits acoustic wave transmitting through an air or an insulator. The acoustic wave between 20 kHz and several hundred of kHz can be detected by piezoelectric ceramic sensor that converts the acoustic wave into an electrical signal. Piezoelectric ceramic sensor has either the wide resonant band or the local resonant band depending on the ceramic material or the various combinations of each different component in the manufacturing process. This paper presents the piezoelectric ceramic sensor with 0.95 PZT–0.05 PMNS that yields the piezoelectric properties of high kp, high Qm. It has the frequency characteristics of local resonant band, such that it can be applied to PD detection. We have demonstrated the properties of the proposed piezoelectric ceramic sensor by comparing with the conventional electrical PD detector. Quantitative analysis is accomplished by comparing the -qmax from a PD detector and the -vmax from the proposed sensor while -n distributions are the same for both the conventional phase-resolved PD analysis method and the proposed one. 相似文献
86.
M. Tsukada H. Yamawaki M. Kondo J. S. Cross K. Kurihara 《Journal of Electroceramics》2004,13(1-3):29-33
Thin films made of (100)/(001)-oriented Pb(Zr, Ti)O3 (PZT) were deposited by liquid-delivery metal-organic chemical vapor deposition on Ir/MgAl2O4/SiO2/Si(100) substrates. For comparison, PZT thin films were also deposited on Ir/MgO(100) substrates. The X-ray scan spectra for the (202) reflections revealed that the PZT films have four-fold symmetry. It indicates that the PZT films were epitaxially grown as a cube-on-cube structure on both substrates. The switchable polarization (Qsw) of the PZT capacitors on the silicon substrate was only 23 C/cm2 at 1.8 V; however, Qsw of PZT capacitors on MgO was 99 C/cm2. In the case of PZT films deposited on silicon, the volume fraction of (001)-oriented domains (which contribute to polarization switching) was 15.1% (calculated from an XRD pattern). This result is due to the lower Qsw of PZT capacitors on silicon. By piezoresponse-force microscopy, switchable and unswitchable domains could be identified by imaging color contrast, namely, (001) and (100) domains, respectively. Consequently, domain distribution of the PZT film on a silicon substrate indicates that the (001) domain exists in the (100) domain matrix. 相似文献
87.
以Pb3O4、ZrO2、TiO2和Nb2O5为原料,按Pb(Zr(0.95)Ti(0.05))O3+1%Nb2O5配料混合,采用柱面冲击波装置对粉料进行冲击合成,研究了冲击波作用对粉体性能和烧结特性的影响,并利用球模型推导的扩散机制的烧结方程获得PZT95/5陶瓷的烧结活化能.结果表明,利用冲击波的高温高压作用可以合成单一钙钛矿相PZT95/5粉体,同时由于冲击波的活化作用和破碎作用,使粉体晶粒细化,并产生了一定程度的晶格畸变,可显著改善陶瓷的烧结性能.该试样在1200℃无压烧结3h,陶瓷体致密度达到7.79g·cm^-3,其烧结活化能由固相合成试样的242.57kJ·mol^-1降低为115.12kJ·mol^-1,起到活化烧结的目的. 相似文献
88.
89.
Federico González María-Elena Villafuerte-Castrejón Alfonso Huanosta 《Journal of Electroceramics》2007,18(3-4):323-327
A Pb0.98Eu0.02(ZryTi1−y
)0.995O3 compound series, with y = 0.60, 0.53 and 0.45 was prepared. PZT samples were synthesized by sol–gel technique. The crystallization and quality of
the compounds were analyzed by powder X-ray diffraction and electron microscopy. The shape of the ε′(ω) vs T curves can be considered typical of a ferro-paraelectric transition. The ferro-paraelectric transition temperature
for each composition was 348, 328 and 307°C, for the y = 0.45, 0.53 and 0.60, respectively. σ′(ω) is strongly influenced by short range processes. For the logσ′(ω) curves as function of temperature, there is evidence of a non dispersive dc-conductivity component for the high temperature
region. The associated dc-activation energies are larger than those calculated for the ac region (at lower temperatures). 相似文献
90.
In this work, fabrication and properties of 3-dimensional structures coated with piezoelectric Pb(Zr,Ti)O3 (PZT) thin films have been studied in order to improve the piezoelectric coupling into the third dimension. Calotte layers
have been chosen as demonstration devices. The base diameters range from 40 to 120 μm, the height varies between 10 to 40 μm.
A dynamic, in-situ co-sputtering process allowing for in-situ growth was applied. Micromoulds were formed by wet etching in
silicon. The etchant was a HNA solution (HF, HNO3, CH3COOH) on a silicon dioxide mask. Calottes were obtained with the desired geometry and smooth surface state after few minutes
etching time, and the use of chemical mechanical polishing (CMP). After deposition of the PZT membrane, deep silicon dry etching
was then used to liberate the calotte layer. The dielectric constant and loss tangent of the calotte capacitors amounted to
830 and 5%, respectively (10 kHz). The fundamental resonance frequencies varied between 2.5 and 16.5 MHz, and were found to
be inversely proportional to the base area of the calotte, the proportionality factor being 0.08 Hz m2. 相似文献