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41.
Tunable dielectric characteristics of 0.9Pb(Fe1/2Nb1/2)O3/0.1CaTiO3 relaxor ferroelectric ceramics were investigated as the function of DC bias field and temperature. High tunability (more
than 20%) was obtained in the present ceramics under a relatively weak DC bias field (1.4 kV/cm). The value of tunability
changed from negative to positive with increasing DC field. For the simulation of the dielectric constant under DC bias field,
modified model needs to be constructed for the relaxor ferroelectrics. The dielectric constant curve as a function of temperature
without and under DC field was well fitted using the equation of diffuse phase transition. The lower εmax, higher Tmax and higher diffuseness parameter under DC field were observed and only the lower εmax contributed to positive tunability. 相似文献
42.
Photodiodes: Schottky‐Barrier‐Controllable Graphene Electrode to Boost Rectification in Organic Vertical P–N Junction Photodiodes (Adv. Funct. Mater. 48/2017)
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43.
Metamaterials: Tailorable Zero‐Phase Delay of Subwavelength Particles toward Miniaturized Wave Manipulation Devices (Adv. Mater. 40/2015)
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44.
45.
Jin Woong Kim Hiromi Shima Hiroshi Funakubo Ken Nishida Takashi Yamamoto 《Integrated ferroelectrics》2014,157(1):101-113
Ba(ZrxTi1-x)O3 (BZT) thin films with different Zr contents were deposited on (100)MgO and (100)Pt/(100)MgO substrates by RF-magnetron sputtering using metal targets. The BZT thin films had a single perovskite phase with only (001)/(100) orientation. In all cases, the ratio of Ba/Ti was stoichiometry and BZT films possess a dense microstructure. The grain size was decreased and BZT thin films showed ferroelectric-to-paraelectric properties with increasing Zr content. At room temperature, the tunability of nearly 30% was achieved at 1 MHz; meanwhile, a relatively low dielectric loss was obtained. These results indicated that we succeeded in depositing high-quality and potential tunable ferroelectrics. 相似文献
46.
研究了Cr掺杂对钛酸锶钡(Ba0.6Sr0.4TiO3,BST)陶瓷的介电及其可调性能的影响.结果表明,少量的Cr可进入BST品格形成固溶体,并促进晶粒生长.当Cr掺杂量(摩尔分数)低于1.0%时,陶瓷的介电损耗急剧降低,调谐率明显提高,综合性能显著改善,其中Cr掺杂0.6%的BST陶瓷具有最佳的综合性能,其在1MHz下的介电损耗为0.0005,品质因子(FoM)达到500,而未掺杂样品的FoM值仅为60.Cr掺杂陶瓷损耗的急剧降低可归因于Cr3 离子的还原和Cr3 、Cr2 受主行为中和了氧空位的施主行为. 相似文献
47.
ABSTRACT Thin films of BaZr0.25Ti0.75O3 in which Ba2 + is partially substituted by Ca2 + are prepared by a sol-gel method. Phases and dielectric properties of the films are studied.The crystal structure of BaZr0.25Ti0.75O3 is cubic and does not change with Ca substitution upto x = 0.25 in Ba1-xCaxZr0.25Ti0.75O3. A change from a normal to relaxor behavior is observed for x = 0.20 as indicated by a change in the frequency of dielectric maxima with temperature and other parameters.The dielectric constant and transition temperatures are found to increase with increasing Ca substitution. A tunabilty of 71%, much higher than reported in literature for this material, is observed for x = 0.1 i.e for Ba0.9Ca0.1Zr0.25Ti0.75O3. 相似文献
48.
《Integrated ferroelectrics》2013,141(1):769-779
Ferroelectric Na0.5K0.5NbO3 (NKN) thin films were grown on the Pt80Ir20 polycrystalline substrates by pulsed laser deposition (PLD) and radio frequency-magnetron sputtering (RF) technique using the same stoichiometric Na0.5K0.5NbO3 ceramic target. X-ray diffraction proved both PLD- and RF-made Na0.5K0.5NbO3/Pt80Ir20 films are single phase and have preferential c-axis orientation. Temperature dependence of dielectric permittivity reveals the presence of two phase transitions around 210 and 410°C. Capacitance vs. applied voltage C-V @ 100 kHz, I-V, and P-E hysteresis characteristics recorded for the vertical capacitive structures yielded loss tanδ = 0.026 and 0.016, tunability about 44.5 and 30% @ 100 kV/cm, Ohmic resistivity 6.7 × 1012 Ω·cm and 0.2 × 1012 Ω·cm, remnant polarization 11.7 and 9.7 μC/cm2, coercive field 28.0 and 94.6 kV/cm for PLD- and RF-films, respectively. Piezoelectric test carried out in hydrostatic conditions showed piezoelectric coefficient d H = 21 for PLD-NKN and 15 pC/N for RF-NKN film. 相似文献
49.
AbstractThis work describes novel surface-enhanced Raman scattering (SERS) substrates based on ferroelectric periodically poled LiNbO3 templates. The templates comprise silver nanoparticles (AgNPs), the size and position of which are tailored by ferroelectric lithography. The substrate has uniform and large sampling areas that show SERS effective with excellent signal reproducibility, for which the fabrication protocol is advantageous in its simplicity. We demonstrate ferroelectric-based SERS substrates with particle sizes ranging from 30 to 70 nm and present tunable SERS effect from Raman active 4-mercaptopyridine molecules attached to AgNPs when excited by a laser source at 514 nm. 相似文献
50.