All solid state ion-conducting cesium source for atomic clocks

Cesium containing glass with solid metal electrodes was used as a Cs atom source in a high vacuum system. A silver anode provides an injection source of highly mobile ions which sweep Cs to the cathode surface, from which they evaporate into the vacuum. Cathode metallization with finger patterns was used leaving bare glass for Cs evaporation. Laser absorption measurements show Cs vapor generation synchronous with an applied DC voltage.     

Meter-long CeO2/YSZ/Y2O3 buffer layers for YBCO coated conductors using DC reactive sputtering

This paper reports CeO₂/YSZ/Y₂O₃ buffer layers deposited on biaxially textured NiW substrates by DC reactive sputtering in a reel-to-reel system. The effect of partial pressure of water vapor (P_H2O) on surface morphology and orientation of the Y₂O₃ films was examined. The obtained CeO₂/YSZ/Y₂O₃ buffer layers exhibit a highly biaxial texture, with in- and out-of-plane FWHM values respectively in the range of 6.0–7.0° and 4.5–5.5°. Crystallographic consistency of CeO₂/YSZ/Y₂O₃ along meter length is excellent. Atomic force microscope observation (AFM) reveals a smooth, continuous and crack-free surface with a Root-mean-square roughness (RMS) lower than 10 nm.     

The influence of substrate surface roughness on microstrip transmission line loss using conventional analyses and length‐scale fractal analysis

Two components of conductor topography can impact conductor loss for signals in the GHz frequency range: conductor–ceramic interface roughness and conductor edge angle. This study is an experimental investigation of the influence of these conductor topographies on conductor loss in microstrip circuits produced by thick‐film technology. The aluminum nitride ceramic substrates have different surface roughnesses due to different surface finish processes. The substrate surfaces were characterized using conventional and length‐scale fractal analysis. The conductor–ceramic interface was measured with a contact profilometer. The conductor edge angle and conductor edge profile were measured optically. It was found that there is a direct correlation between conductor loss and conductor edge angle, whereas there is an inverse correlation between loss and substrate roughness or relative length of the conductor–ceramic interface. This is the opposite result to the conventional expectation of surface roughness effects on conductor loss. There is also a negative correlation between conductor edge angle and surface roughness or relative length. The loss behavior can be explained by the interaction of the conductor paste with the surfaces during processing. The paste tends to spread more on the smoother surfaces, and thus creates an elongated edge of diminishing cross‐section and a small edge angle. This leads to greater conductor loss. Copyright © 2009 John Wiley & Sons, Ltd.     

镜像系统和镜像天线

对电荷电流体系在理想导体平面所形成的镜像系统的各物理量作了全面分析，并得出镜像天线的结果。     

超高介电常数非铁电单晶

关键词：     

半导体超晶格属性的高分辨率X射线衍射研究

详细阐述了低维半导体材料的X射线衍射的动力学理论和运动学理论从高木陶平(T-T)方程出发,基于波动光学原理,推导出任意结构的多层膜的X射线衍射振幅的递推关系式并编写X射线衍射的程序,分别用动力学和运动学衍射理论模型模拟了20层GaAlAs/GaAs超晶格的X射线衍射结果,得到超晶格样品的结构参量.     

在电磁学中介绍迁移率的概念

引入迁移率的概念，可以以简捷、通俗的方式帮助理解导体、半导体、等离子体、气体和液体中不同的导电机制、半导体的电导率随温度升高而敏锐地升高的原因，以及半导体的导电性能为什么可以通过掺入杂质原子的数量来有效的控制。     

Li17Sb13S28: A New Lithium Ion Conductor and addition to the Phase Diagram Li2S–Sb2S3

Li₁₇Sb₁₃S₂₈ was synthesized by solid‐state reaction of stoichiometric amounts of anhydrous Li₂S and Sb₂S₃. The crystal structure of Li₁₇Sb₁₃S₂₈ was determined from dark‐red single crystals at room temperature. The title compound crystallizes in the monoclinic space group C2/m (no. 12) with a=12.765(2) Å, b=11.6195(8) Å, c=9.2564(9) Å, β=119.665(6)°, V=1193.0(2) ų, and Z=4 (data at 20 °C, lattice constants from powder diffraction). The crystal structure contains one cation site with a mixed occupation by Li and Sb, and one with an antimony split position. Antimony and sulfur form slightly distorted tetragonal bipyramidal [SbS₅E] units (E=free electron pair). Six of these units are arranged around a vacancy in the anion substructure. The lone electron pairs E of the antimony(III) cations are arranged around these vacancies. Thus, a variant of the rock salt structure type with ordered vacancies in the anionic substructure results. Impedance spectroscopic measurements of Li₁₇Sb₁₃S₂₈ show a specific conductivity of 2.9×10^?9 Ω^?1 cm^?1 at 323 K and of 7.9×10^?6 Ω^?1 cm^?1 at 563 K, the corresponding activation energy is E_A=0.4 eV below 403 K and E_A=0.6 eV above. Raman spectra are dominated by the Sb?S stretching modes of the [SbS₅] units at 315 and 341 cm^?1 at room temperature. Differential thermal analysis (DTA) measurements of Li₁₇Sb₁₃S₂₈ indicate peritectic melting at 854 K.     

Hydrothermal synthesis of peony-like CuO micro/nanostructures for high-performance lithium-ion battery anodes

The peony-like CuO micro/nanostructures were fabricated by a facile hydrothermal approach. The peonylike CuO micro/nanostructures about 3-5 μm in diameter were assembled by CuO nanoplates. These CuO nanoplates, as the building block, were self-assembled into multilayer structures under the action of ethidene diamine, and then grew into uniform peony-like CuO architecture. The novel peony-like CuO micro/nanostructures exhibit a high cycling stability and improved rate capability. The peony-like CuO micro/nanostructures electrodes show a high reversible capacity of 456 mAh/g after 200 cycles, much higher than that of the commercial CuO nanocrystals at a current 0.1 C. The excellent electrochemical performance of peony-like CuO micro/nanostructures might be ascribed to the unique assembly structure, which not only provide large electrode/electrolyte contact area to accelerate the lithiation reaction, but also the interval between the multilayer structures of CuO nanoplates electrode could provide enough interior space to accommodate the volume change during Li~+ insertion and de-insertion process.