电解有机溶液法在Si表面制备类金刚石薄膜及退火对其结构的影响

在对不同有机溶剂分子结构分析的基础上,选取甲醇、DMF(N,N-二甲基甲酰胺)和乙腈溶液为碳源,以脉冲直流电源电解有机溶液的方法在Si片上制得了含氢类金刚石薄膜(DLC薄膜),并研究了退火对薄膜结构的影响.通过X射线光电子能谱(XPS),喇曼(Raman)和红外(IR)光谱对薄膜的结构进行了分析表征.XPS表明薄膜的主要成分为C,喇曼光谱显示所得薄膜为典型DLC薄膜.喇曼和红外光谱还表明,膜中含有大量H并且主要键合于sp³碳处.随着退火的进行薄膜中的H被去除.随温度升高薄膜电阻率的下 关键词： 类金刚石薄膜 退火     

Interface diffusion and chemical reaction of PZT layer/Si (111) sample during the annealing treatment in air

The interface diffusion and chemical reaction between a PZT (PbZrxTi1-xO3) layer and a Si(111) substrate during the annealing treatment in air have been studied by using XPS (X-Ray Photoelectron Spectroscopy) and AES (Auger Electron Spectroscopy). The results indicate that the Ti element in the PZT precursor reacted with residual carbon and silicon, diffused from the Si substrate, to form TiCx, TiSix species in the PZT layer during the thermal treatment. A great interface diffusion and chemical reaction took place on the interface of PZT Si also. The silicon atoms diffused from silicon substrate onto the surface of PZT layer. The oxygen atoms, which came from air, diffused into silicon substrate also and reacted with Si atoms to form a SiO2 interlayer between the PZT layer and the Si (111) substrate. The thickness of SiO2 interlayer was proportional to the square root of treatment time. The formation of the SiO2 interlayer was governed by the diffusion of oxygen in the PZT layer at low annealing tempera     

超声振子箝位压电直线微动马达研究

本文提出一种利用环形三叠片超声振子箝位的压电直线微动马达.这种马达的箝位振子与导轴形成摩擦付。振子共振时其动摩擦系数与静摩擦系数之比降为～0.1。箝位振子的激励电压仅为±80V(峰峰值).马达速度为0—2mm/min;位移分辨率为50nm;驱动力约0.2kgf.这种马达还具有工艺简单的特点.     

压电陶瓷超声波马达

压电陶瓷超声波马达是利用压电陶瓷材料激发超声波实现驱动的一种新型电机,同传统的电磁马达和静电马达比较,它具有低速下大力矩输出、无电磁干扰、静音操作、保持力矩大、响应速度快、结构简单等特点.在国外,它已经在精密仪器、航天航空、自动控制、办公自动化、微型机械系统、微装配、精密定位等领域得到了实际应用.文章系统地总结了压电陶瓷声马达的特点,简略介绍了国内外相关技术的发展情况及前沿性研究方向,并提出进一步开发研究的几点建议,希望会对我国压电陶瓷声马达的研究以及相应产品的开发起到积极的促进作用.     

Fabrication and characterization of direct-written 3D TiO_2 woodpile electromagnetic bandgap structures

Three groups of three-dimensional(3D) TiO2 woodpile electromagnetic gap materials with tailed rheological properties were developed for direct-written fabrication. Appropriate amount of polyethyleneimine(PEI) dispersants allow the preparation of TiO2 inks with a high solid content of 42 vol.%, which enables them to flow through the nozzles easily.The inks exhibit pseudoplastic behavior. The measured microwave characteristics of the results agree well with simulations based on plane wave expansion(PWE).     

Ferroelectric and dielectric properties of La/Mn co-doped Bi4Ti3O12 ceramics

La/Mn co-doped Bi4Ti3O12 ceramics,Bi3.25La0.75Ti3-xMnxO12(x=0.02,0.04,0.06,0.08),were prepared by the solid-state reaction method.The influence of manganese substitution for the titanium part in Bi 3.25 La 0.75 Ti 3 O 12 on the sintering behaviour,microstructure,Raman spectra and electrical properties was investigated.The experimental results show that the phase composition of all samples with and without manganese doping,sintered at 1000 ℃,consists of a single phase with a bismuth-layered structure belonging to the crystalline phase Bi4Ti3O12.There is no evidence of any impurity phase,but a small change in crystallographic orientation is observed.The Curie temperature of Bi3.25La0.75Ti3-xMnxO12 ceramics is steadily shifted to lower temperature with increasing Mn-doping content.Moreover,the remnant polarisation(Pr) of Bi3.25La0.75Ti2.92Mn0.08O12 samples increases with Mn-doping content,and the Bi3.25La0.75Ti2.92Mn0.08O12 sample exhibits the largest P r of 16.6 μC/cm 2.     

高分辨特性压电行波旋转马达研究

本文对一种压电行波型旋转超声马达进行了理论与实验研究。采用有限元方法对行波马达驱动定子的各阶振动模式、谐振频率进行了分析；研制的行波马达具有以下特点：低转速（0－50r．p．m）、较大力矩输出（0~1．9kgf．cm）、自锁功能、高的角分辨率和定位精度（±0.15°）。     

掺杂的PbTiO_3铁电陶瓷中的正电子湮没

正电子湮没技林(PAT)在材料缺陷的研究中有着广泛的应用[1].但它用于铁电陶瓷组分缺陷的研究则刚刚开始.Tsuda[2,3]等研究了掺Gd的BaTiO3的正电子寿命谱,证明正电子对掺Gd所造成的Ba空位是敏感的.本文报道La,Mn复合置换的PbTiO3铁电陶瓷的正电子寿命谱测量结果.样品配料分子式为(Ph-(1-1.5x)其中表示Pb空位,x值从1%到10%.样品按陶瓷工艺制成20 ×20×1mm3薄方片.在室温(23℃)下进行正电子寿命测量,实验所用的ORTEC系列快定时系统正电子寿命谱仪在测量 CO～(60)的瞬发曲线时的半高宽(FWHM)为280ps. 用正电子拟合(POSITRONFIT…     

超细钛酸钡的表面改性

利用Sol-gel法成功地在超细钛酸钡粉体表面包覆了厚度约5nm的均匀SiO2膜。采用HRTEM,XPS和XRD等多种分析方法,证实了SiO2薄膜的存在。并首次提出钛酸钡水解后水玻璃在TiO2-x表面溶胶-凝胶化的包覆机理。改性后的钛酸钡与纯钛酸钡相比,SiO2包覆可促进烧结,包覆SiO2坯体在1190℃达到最大收缩速率,而纯钛酸钡坯体达到最大收缩速率的温度为1260℃。坯体的收缩率由未包覆前的-15%变化到-19.3%。包霖工艺改善了介电性能,使介温曲线平坦,对制造钛酸钡薄层电容器有重要的价值。     

具有梯度结构的蛋白石光子晶体的制备

具有梯度结构的蛋白石光子晶体具有独特的光学性能。本文通过垂直沉积法和电场诱导沉积等方法共同作用将具有不同直径的聚苯乙烯(Polystyrene)胶体微球逐层组装在一起,制备出具有梯度周期尺寸变化的蛋白石结构。