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1.
The metal-ferroelectric-semiconductor (MFS) heterostructure has been fabricated using Bi3.25La0.75Ti3O12 (BLT) as a ferroelectric layer by sol-gel processing. The effect of annealing temperature on phase formation and electrical
characteristics of Ag/BLT/p-Si heterostructure were investigated. The BLT thin films annealed at from 500°C to 650°C are polycrystalline,
with no pyrochlore or other second phases. The C-V curves of Ag/BLT/p-Si heterostructure annealed at 600°C show a clockwise C-V ferroelectric hysteresis loops and obtain good electrical properties with low current density of below 2×10−8 A/cm2 within ±4 V, a memory window of over 0.7 V for a thickness of 400 nm BLT films. The memory window enlarges and the current
density reduces with the increase of annealing temperature, but a annealing temperature over 600°C is disadvantageous for
good electrical properties. 相似文献
2.
Ceramics with formula (1 − x)Pb(Zr0.52Ti0.48)O3–x(Bi3.25La0.75)Ti3O12 (when x = 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) were prepared by a solid-state mixed-oxide method and sintered at temperatures between 950 °C and 1250 °C. It was found that the optimum sintering temperature was 1150 °C at which all the samples had densities at least 95% of theoretical values. Phase analysis using X-ray diffraction indicated the existence of BLT- as well as PZT-based solid solutions with corresponding lattice distortion. Scanning electron micrographs of ceramic surfaces showed a plate-like structure in BLT-rich phase while the typical grain structure was observed for PZT-rich phase. The grain sizes of both pure BLT and PZT ceramics were found to decrease as the relative amount of the other phase increased. This study suggested that tailoring of properties of this PZT–BLT system was possible especially on the BLT-rich side due to its large solubility limit. 相似文献
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Over the last couple of years molecular imaging has been rapidly developed to study physiological and pathological processes in vivo at the cellular and molecular levels. Among molecular imaging modalities, optical imaging stands out for its unique advantages, especially performance and cost-effectiveness. Bioluminescence tomography (BLT) is an emerging optical imaging mode with promising biomedical advantages. In this survey paper, we explain the biomedical significance of BLT, summarize theoretical results on the analysis and numerical solution of a diffusion based BLT model, and comment on a few extensions for the study of BLT. 相似文献
4.
Time-domain analytic solutions of two-wire transmission line excited by a plane-wave field
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This paper reports that an analytic method is used to calculate the load responses of the two-wire transmission line excited by a plane-wave directly in the time domain. By the frequency-domain Baum Liu-Tesehe (BLT) equation, the time-domain analytic solutions are obtained and expressed in an infinite geometric series. Moreover, it is shown that there exist only finite nonzero terms in the infinite geometric series if the time variate is at a finite interval. In other word, the time-domain analytic solutions are expanded in a finite geometric series indeed if the time variate is at a finite interval. The computed results are subsequently compared with transient responses obtained by using the frequency-domain BLT equation via a fast Fourier transform, and the agreement is excellent. 相似文献
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This paper is concerned with an ill-posed problem which results from the area of molecular imaging and is known as BLT problem. Using Tikhonov regularization technique, a quadratic optimization problem can be formulated. We provide an improved error estimate for the finite element approximation of the regularized optimization problem. Some numerical examples are presented to demonstrate our theoretical results. 相似文献
7.
本文基于等效电路法, 提出一种通过BLT方程计算带孔缝箱体屏蔽效能的方法, 可以快速准确计算任意入射、极化平面波照射箱体以及任意位置开孔和双面开孔箱体的屏蔽效能. 根据等效电路法求解出孔缝散射矩阵, 依据信号流图建立传播关系和散射关系方程, 并推导出包含孔缝耦合效应的广义BLT方程. 将BLT方程计算结果与等效电路法计算结果以及CST仿真做对比, 验证了方法的正确性. 与等效电路法相比, 在同一孔阻抗下, 孔缝散射矩阵包含箱体内外能量之间的相互耦合作用, 本方法计算结果精度更高, 能预测更多箱体谐振模式; 与CST仿真相比, 本方法占用时间和资源少, 可以对箱体参数进行规律性研究. 相似文献
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B.I. Seo U.A. Shaislamov S.-W. Kim H.-K. Kim B. Yang S.K. Hong 《Physica E: Low-dimensional Systems and Nanostructures》2007,37(1-2):274
We report results of fabrication and examination of Bi3.25La0.75Ti3O12 (BLT) ferroelectric nanotubes. BLT nanotubes are suggested for developing 3D ferroelectric nanotube capacitors which could be used in high-density memory applications. BLT nanotubes were prepared by template-wetting process using polymeric sources where anodic aluminum oxide had been used as a template. After annealing, tubular BLT structures were crystallized inside the pores of the template. By selective etching of the template, released BLT nanotubes have been obtained. Crystallization and nucleation of the nanotubes were analyzed by XRD and FE-SEM techniques. 相似文献
10.
c-Axis-oriented and (1 1 7)-oriented Bi3.25La0.75Ti3O12 (BLT) thin films are successfully controlled by the intermediate layer of LaNiO3 (LNO) with chemical solution deposition (CSD), respectively. X-ray diffraction (XRD) demonstrates that the structure and orientation of LNO thin films have a strong effect on the orientation of BLT thin films. Scanning electron microscopy suggests that BLT thin films on LNO electrode exhibit crack-free, uniform size grains and dense microstructure. A crystalline orientation dependent remanent polarization is observed in BLT thin films, and it is found that the remanent polarization (2Pr) of (1 1 7)-oriented films is larger than that of c-axis-oriented films. Our research directly demonstrates that the vector of the main spontaneous polarization in these layered perovskite materials (BLT) is along a-axis. 相似文献