Influence of annealing on the structure and stoichiometry of europium-doped titanium dioxide thin films

This work presents the influence of annealing on the structure and stoichiometry of europium (Eu)-doped titanium dioxide (TiO₂). Thin films were fabricated by magnetron sputtering from a metallic Ti-Eu target in oxygen atmosphere and deposited on silicon and SiO₂ substrates. After deposition the selected samples were additionally annealed in air up to 1070 K.Film properties were examined by means of X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) and the results were analyzed together with the undoped TiO₂ thin films prepared under similar technological conditions.XRD results showed that depending on the Eu content, as-deposited thin films consisted of the TiO₂-anatase or TiO₂-rutile.An additional annealing will result in the growth of anatase crystals up to 35 nm, but anatase to rutile phase transformation has not been recorded. AFM images display high quality and a dense nanocrystalline structure. From the XPS Ti2p spectra the 4+oxidation state of Ti was confirmed. The O1s XPS spectra displayed the presence of an O²⁻ photoelectron peak accompanied by an additional broader peak that originates from hydroxyl species chemisorbed at the sample surface. It has been found that Eu dopant increases the OH⁻ content on the surface of prepared TiO₂:Eu thin films. The calculated O/Ti ratio was in the range of 1.85-2.04 depending on the sample.     

溅射功率对TaN薄膜电阻电性能的影响

本文利用直流反应磁控溅射技术,通过调节溅射功率于200℃、3％的氮分压条件在Al2O3基片上沉积了一系列TaN薄膜,并使用光刻工艺制备出相应的TaN薄膜电阻,研究了溅射功率对TaN薄膜电阻率、电阻温度系数（TCR）和功率容量的影响。实验结果表明：当溅射功率从200W增大到1000W,TaN薄膜电阻率逐渐减小,TCR绝对值从几百ppm／℃降为几十ppm／℃,功率容量呈现逐渐增大趋势。     

电容器故障监测系统的应用研究

基于近年并联电容器装置频繁出现故障的现象和特点,研制出一套电容器故障监测系统,分别提取并联电容器装置的电流和电压实时信号,利用Labview虚拟仪器程序进行软件开发实现在线监测,对获取的电流电压信号进行谐波、合闸涌流、暂态过电压等方面进行分析和研究,并应用于现场测量,给出了一起电容器内部击穿故障的监测实例。     

智能低压配变监测与无功率补偿箱设计探索

针对现有的配变监测与无功补偿箱使用中存在的诸多问题,通过在结构上找原因,从性能上找差距的方式,进行了多层面的分析、对比和研究,提出了智能化、模块化的全新设计理念,科学地实现了低压配电监测与智能无功补偿装置的有机组织。     

基于遗传算法的变电站电压无功自动控制

针对当前用户无功负荷激烈变化时,变电站电压无功自动控制装置动作频繁的缺陷,提出一种基于遗传算法的变电站电压无功综合控制方法,并通过仿真计算,结果表明该方法是有效的。     

无功、负序及谐波电流检测中的数字滤波器研究

数字滤波器是基于瞬时无功理论的无功、负序及谐波电流检测中一个重要部分,其精度和速度直接影响检测的结果。文中在各种电压和电流情况下对电流检测中所需要的数字滤波器进行分析,得出数字滤波器分类设计的想法,并优化设计出三种适用于不同电压和电流情况的数字滤波器。仿真和实验结果证明所设计的数字滤波器与目前电流检测中使用的数字滤波器相比,在保证精度的同时能有效提高速度,且本身算法的复杂性并未显著增加。     

Patterning issues for the fabrication of sub-micron memory capacitors' electrodes

This paper describes some of the key issues associated with the patterning of metal electrodes of sub-micron (especially at the critical dimension (CD) of 0.15 μm) dynamic random access memory devices. Due to reactive ion etching lag, the Pt etch rate decreased drastically below the CD of 0.20 μm and thus K-th storage node electrode with the CD of 0.15 μm could not be fabricated using the Pt electrodes. Accordingly, we have proposed novel techniques to surmountly-the above difficulties. The Ru electrode cannot for the stack-type structure is introduced and alternative multischemes based on the introduction of the concave-type selfstructure upto using semi-Pt or Ru as an electrode material are outlined respectively.     

Luminescence hydrogenated nanoamorphous Si films fabricated by reactive pulsed laser ablation

Hydrogenated nanoamorphous Si (na-Si:H) films have been fabricated by reactive pulsed laser ablation technique with hydrogen as reactive gas. It is found that the hydrogen pressure has a great effect on both the structure and photoluminescence (PL) properties of the films. Increasing the hydrogen pressure leads to a structural transition of the films from amphorous Si to na-Si:H, and the PL center wavelength of the na-Si:H films is varied with the hydrogen pressure. The PL decay times of the na-Si:H films are in the nanosecond scale and are shorter on the high energy side of their PL spectrum. The results demonstrate that the na-Si:H films are promising candidates for visible, tunable and high-performance light-emitting devices.     

无功补偿装置及应用（五）

本文讲述了无功补偿的基本概念,介绍了各种无功补偿装置的原理和应用。     

科学改造无功补偿装置减少电费支出

分析了功率因数偏低的原因,主要原因有原有低压无功补偿装置设计不合理,器件出现故障,不能提供系统所需的无功补偿功率。通过实例给出了无功补偿装置改造的具体做法,如加装电抗器,选用耐压等级合适的电容器,采用无功补偿装置专用交流接触器,并合理规划了无功补偿柜内散热通道。最后对改造前后的经济效益进行了分析。