Structural Variation and Its Influence on the 1/f Noise of a-Si_(1-x)Ru_x Thin Films Embedded with Nanocrystals

The structural variation and its influence on the 1/f noise of a-Si_(1-x)Ru_x thin films are investigated by Raman spectroscopy,transmission electron microscopy, and low frequency noise measurement. The Ru atoms are introduced into the amorphous silicon thin films by rf magnetron co-sputtering. Ru2 Si nanocrystals are found in the as-deposited samples. It is shown that the 1/f noise of the films can be reduced by a slight doping with Ru atoms. Moreover, both the microstructure and the 1/f noise performance of a-Si_(1-x)Ru_x thin films could be improved through a high-temperature annealing treatment.     

激光反射镜与诱导透射滤光片工艺分析

随着光通信和光信息技术的迅速发展,介质高反射镜和窄带滤光片倍受人们关注,有机光学薄膜滤波器材料及器件将日益受到重视.采用一个低通滤波器和高通滤波器在其通带叠合处便可产生一个优良的窄带滤波器.详细介绍了几种光学薄膜器件激光反射镜、诱导透射滤光片(ITF)和微片式激光器的混合材料及制备工艺,并给出其设计方法,对批量生产将有极大的促进作用.     

基于logistic模型的我国信息产业演化发展研究

信息产业作为战略性新兴产业,对国民经济的发展发挥着巨大的推动作用.对于信息产业演化发展路径的深入探索,有利于增强信息产业发展战略的科学性和前瞻性.基于logistic成长模型,高精度拟合中国信息产业、信息制造业和信息服务业的演化发展历程,详细揭示中国信息产业及其产业部门的演化发展规律.研究结果表明:我国信息产业及其产业部门的演化发展速度,均符合先慢再快后慢的成长规律;我国信息服务业的发展速度和发展潜力均强于信息制造业,但信息制造业的业态总量远超过信息服务业;总体而言,我国信息产业及其产业部门目前正处于成长后期,发展势头强劲.     

京津冀协同发展背景下河北省信息产业关联效应分析

信息产业作为京津冀协同发展的战略重点,其价值创造过程,与各产业部门之间存在直接或间接的产业关联,以此直接或间接地带动经济发展.采用投入产出分析法,以河北省2012年投入产出表为依据,定量分析河北省信息制造业和信息服务业对各产业部门的经济关联效应.研究结果表明:河北省信息制造业主要以需求上游相关产业投入的形式,拉动各产业部门发展;而河北省信息服务业则主要以供给下游相关产业生产的方式,推动各产业部门发展;并且河北省信息制造业对各产业部门的总体关联程度,强于信息服务业,即河北省信息制造业更能够广泛地影响经济发展.     

Flexible tuning microwave permeability spectrum in [ferromagnet/antiferromagnet]_n exchange-biased multilayer stack structure

NiFe/[IrMn/NiFe/IrMn] 5 /[NiFe/IrMn] 4 /NiFe structured exchange-biased multilayer films are designed and prepared by magnetron sputtering. The static and the microwave magnetic properties are systematically investigated. The results reveal that adding a partially pinned ferromagnetic layer can effectively broaden the ferromagnetic resonance linewidth toward the low frequency domain. Moreover, a wideband multi-peak permeability spectrum with a 3.1-GHz linewidth is obtained by overlapping the spectra of different partially pinned ferromagnetic layers and [antiferromagnet/ferromagnet/antiferromagnet] n stacks. Our results show that the linewidth of the sample can be feasibly tuned through controlling the proper exchange bias fields of different stacks. The designed multilayered thin films have potential application for a tunable wideband high frequency noise filter.     

基于Logistic模型的创新生态系统的种群关系研究

京津冀产业创新生态系统是京津冀协同发展的重要内容.从产业创新生态系统外部和内部两个角度对京津冀电子信息制造业创新生态系统进行剖析,一方面运用生态学理论构建京津冀电子信息制造业创新生态系统,借用Logistic模型分析京津冀区域电子信息制造业创新生态系统种群间的动态演化,协同效应初步显现;另一方面结合仿真方法模拟研究京津冀电子信息制造业创新生态系统内部各类种群之间的演化关系和演化规律.互惠共生是电子信息制造业创新生态系统演化的最佳关系模式.各创新主体之间不同的演化关系导致动态创新生态系统不同的演化方向,最终达到平衡状态,并提出相应对策建议.     

Soft Magnetic Thin Films FeCoHfO for High-Frequency Noise Suppression Applications

A series of FeCoHfO films were fabricated by dc magnetron reactive sputtering at varying partial pressure of oxygen （Po2） from 0 to 11.7%, and the electrical and magnetic properties of films have been studied. It is shown that optimal Fe43.29 Co19.51Hf7.49 O29.71 films with desired properties can be obtained when the films were prepared under Po2= 5.1%. The films show superior properties of low coereivity, Hc ∽5.5 Oe, relatively high saturation magnetization, 47rMs · 18.3 kG, high anisotropy field Hk ∽ 65 Oe, and high electrical resistivity ρ∽ 2675 μΩ·cm. Permeability spectra shows that the natural ferromagnetic resonant frequency is as high as 3.1 GHz. The combined merits of the film make the films taken as an ideal candidate material for high-frequency applications such as noise suppressor. In addition, the effects of the film thickness and annealing treatment on the magnetic properties are also reported.     

Theoretical Investigations on the Off-Center Displacement of Co2+ in SrO by Analyzing Its Anisotropic g Factors

The off-center displacement of Co^2＋ ion in SrO crystal is investigated by analyzing its anisotropic g factors gx, gy and gz through diagonalization of the 6 × 6 energy matrix within ^4T1 ground state for a 3d^7 ion under rhombic symmetry. In the matrix, the contributions from the admixtures of various J（= 1/2, 3/2, 5/2） states and the fourth-order term Dn of rhombic crystal-fields and the ligand orbitals and spin-orbit coupling interactions, which are usually ignored in the previous studies, are considered. Both g factors （gx = 4.172, gy = 5.004 and gz = 2.133） and the off-displacement value （△ R ≈ 0.023 am） show good agreement with the experimental data.     

Effects of Layer Deposition Sequence on Microstructure and Magnetostatic Coupling of Spin-Valves with Amorphous CoNbZr Layer

We investigate spin-valve sandwiches with thin amorphous CoNbZr as soft layers. The magnetoresistance (MR), microstructure, and magnetostatic coupling are studied in these sandwiches with different layer deposition sequences. For the CoNbZr/Cu/Co sandwich, the CoNbZr underlayer provides a smoother surface on which smooth Cu and Co layers can subsequently grow. The Cu spacer is dense and pinholes-free, leading to a good ““spin valve““ effect with a larger MR ratio of 3.8%. For the Co/Cu/CoNbZr sandwich, however, the Cu spacer is rough and pinholes were observed, which could induce a direct ferromagnetic coupling. Correlated rougher surfaces on both the sides of the Cu spacer were also observed, giving rise to an ““orangepeel““ coupling of about O. 105 erg/cm^-2. This strong ferromagnetic coupling in Co/Cu/CoNbZr results in a lower MR ratio of 1.6%. Moreover, upon proper thermal annealing, the CoNbZr/Cu/Co has a larger MR enhancement and a superior thermal stability to 350℃ due to the dense and homogenous structure in the spacer layer.     

透明导电半导体ZnO膜的研究

本文采用独特的电子束蒸镀方法，在光学镀膜机上，以 ＺｎＯ＋３％Ａｌ２Ｏ３和 ＺｎＯ为膜料．ｋ９光学玻璃为衬底，制备出ＺｎＯ 膜。膜层为多晶膜，可见光透过率为Ｔ＝７０－９０％，电阻率ｐ＝１×１０－５Ω·ｍ，方电阻为 Ｒ　＝１５０±５０±５０Ω／　，膜机械强度超过国标单层标准，找到实用最佳工艺条件。