单层聚酰亚胺LB膜的STM成象

扫描隧道显微镜(STM)被用来表征聚酰亚胺LB膜的形貌及分子排列结构。本文介绍了单层聚酰亚胺LB膜样品制备过程,所用的STM系统及STM实验。给出了该LB膜亚胺化前后的STM图象。结果表明,所制备的LB膜的聚合链排列有序,测得链间距即横向周期～7(?),纵向上所谓的“之”字型结构的周期为11(?)。这些数值与根据分子面积在理论上所预估的结果相符。     

有机功能薄膜的超高密度信息存储

超高密度信息存储研究是纳米电子学的重要研究领域,有机功能薄膜以其独特的性质有可能成为超高密度信息存储介质之一。利用ＳＴＭ研究了Ｎ,Ｎ－二甲基－Ｎ－（３－硝基苯叉）－对苯二胺（ＤＭＮＢＰＤＡ）有机薄膜的存储特性。高分辨扫描电子显微镜的结果表明,在扫描过程中ＳＴＭ对ＤＭＮＢＰＤＡ薄膜表面进行了二次加工,显微Ｒａｍａｎ谱表明在加工区依然存在着ＤＭＮＢＰＤＡ薄膜,并用原子力显微镜表征了加工区薄膜的表面形貌     

铜硅取代的酞青材料LB膜气敏传感器的研究

采用ＬＢ膜技术对沉积在石英晶振的铜硅取代的酞青材料的气体敏感性进行了系统研究，结果表明，该方法所获得的敏感膜敏感度高，反应迅速，稳定性较好。     

基于SPM的花生酸LB膜的拉膜工艺及结构表征的研究

通过扫描探针显微镜（SPM）直接观察沉积在基片表面的花生酸LB（Langmuir-Blodgett）薄膜不同范围尺度下的微观结构.研究在经过表面两亲性（亲水性或疏水性）处理的基片上,在相同的制膜条件下,改变其拉膜沉积方式,对花生酸LB膜样品的表面结构、薄膜均匀性和缺陷等的影响.结果显示,花生酸LB膜在不同拉膜沉积方式下,薄膜表面将形成不同的分子自组装形态;改变基片表面的亲水性强弱也直接影响LB膜的表面形貌的均匀性,可能通过选择恰当表面处理和沉积方式来获得平整度更高,缺陷更少的LB膜.     

对数字电影摄影机内装超高密度非磁性存储器的先导性研究

本文介绍了创新性超高速大容量电子记录技术，其电子束需借助碳纳米技术生成。文中讲解了形成其电子束的物理过程，分析了电子束的基本特性，提出了存储器的设计方案。与现行磁性硬盘存储器相比，电子束存储器可提供更大的存储容量和更高的存取速率。它的一种可能应用是作为数字摄影机的可移动存储设备。[编者按]     

基于STM/AFM技术的信息存储材料研究现状及进展

信息技术的发展要求存储器件必须具备超高存储密度、超快的存取速率，因而能在纳米尺度上实现信息存储功能的新型超高密度信息存储材料已经成为信息技术领域的研究热点。简要地介绍了近年来利用扫描隧道显微镜／原子力显微镜（STM／AFM）实现信息写入的纳米信息存储材料的研究进展，并进一步列举了尚待解决的问题。     

基于超高密度信息存储薄膜制备的研究进展

信息技术的发展要求存储器件必须具备超高存储密度、超快的存取速率.存储介质是高密度信息存储研究中的基本问题,目前几乎所有的超高密度存储技术都是在薄膜介质上实现的.薄膜的性质除依赖于存储介质材料外还依赖于薄膜的制备技术.从存储介质薄膜的制备角度介绍了超高密度信息存储的研究进展.     

C60/花生酸混合LB膜Ⅲ.LB膜的酸、碱稳定性

用紫外可见吸收光谱(Uv-vis)、x光电子能谱(XPS)和原子力显微镜(AFM)对C60/AA混合LB膜中C60分子在LB膜中的排列作了观察,进一步证明了我们在第一报中确认的在混合LB膜中C60分子不是顶在花生酸疏水部分的端头,而是嵌埋在花生酸分子之间。     

C_(60)/花生酸混合LB膜Ⅱ.LB膜的表征和AFM形貌观察

用紫外可见吸收光谱 (UV -vis)、X光电子能谱(XPS)和原子力显微镜 (AFM)对C60 /AA混合LB膜中C60 分子在LB膜中的排列作了观察 ,进一步证明了我们在第一报中确认的在混合LB膜中C60 分子不是顶在花生酸疏水部分的端头 ,而是嵌埋在花生酸分子之间。     

DPPC/胆固醇混合LB膜的AFM研究

用LB膜技术将二棕榈酰磷脂酰胆碱(DPPC)和胆固醇的混合液转移到疏水云母上,并利用原子力显微镜(AFM)在空气中表征了LB膜的性质。结果表明,当C(DPPC)∶C(cho lestero l)=2.6∶1,膜压15mN/m时,能形成有缺陷的LB膜。并分析了这种缺陷LB膜的形成过程。此法制得的LB膜接近受损伤的肾上皮细胞膜,用于诱导晶体生长,从而建立受损伤的肾上皮细胞膜导致肾结石形成的化学模型。     

CdS纳米粒子的LB膜自组装研究

采用杯[8]衍生物的LB膜成功制备了尺寸可控的CdS纳米微粒.并用AFM、吸收谱、PL谱对其表面形貌和光学性能进行了研究.吸收谱表明循环1次时CdS纳米粒子的吸收边为425nm,这个值同体材料的520nm相比发生了明显的蓝移.随着循环次数的增加,CdS纳米粒子的吸收边逐渐红移,当循环3次时,其吸收边已经移到475nm,这表明纳米粒子的粒径在逐渐长大.CdS纳米粒子的PL谱表明,随着循环次数的增加,其发射峰值逐渐红移,这可能是由于量子尺寸效应造成的.     

Creation of nanostructures on nickel thin films by STM

A scanning tunneling microscope (STM) has been used to create nanostructures on nickel thin films. A systematic procedure for the creation of such structures has been developed. Various possible mechanisms involved in such creations have been discussed. Based on our observations, a field-induced suction of the plastically deformed surface has been proposed.     

Controlled lateral manipulation of molecules on insulating films by STM

On metallic and semiconductor surfaces functional nanostructures can be built with atomic scale precision using the tip of an atomic force microscope/scanning tunneling microscope. In contrast, controlled lateral manipulation on insulators has not been reported. The traditional pushing and pulling based manipulation methods cannot be used for molecules adsorbed on insulating films because of the unfavorable ratio between diffusion barrier and desorption energy. Here, we demonstrate that molecules adsorbed on insulating films can be laterally manipulated in a controlled way by injecting inelastically tunneling electrons at well-defined positions in a molecule. The technique was successfully applied to several different molecules.     

Polycrystalline silicon films fabricated by rapid thermal annealing

Poly-crystalline silicon (poly-Si) films were fabricated by rapid thermal annealing (RTA) of amorphous silicon films which were deposited on quartz by hot wire chemical vapor deposition. An insertion of Cr layer can significantly suppress the peeling of Si films during the RTA process. The effect of RTA parameters on the structural properties of poly-Si films was investigated by Raman spectroscopy, X-ray diffraction and scanning electron microscopy. The results show that the crystallinity of the poly-Si films is increased with the increase of RTA temperature and duration. A sharp peak at about 520?cm^?1 is observed in the Raman spectra of poly-Si films annealed at 900 and 1,100?°C for 15?s indicating the excellent crystallinity of the poly-Si films fabricated by RTA. Poly-Si films with high crystalline fraction of 97.3?% were obtained by RTA at 1,100?°C for 20?s.     

PLD方法制备CaCu3Ti4O12薄膜结构研究

采用脉冲激光沉积法(PLD)分别在LaAlO3(100)以及MgO(100)基片上,在不同的沉积温度下,制备具有体心立方类钙钛矿结构的CaCu3Ti4O12(CCTO)薄膜.在LAO基片上生长的CCTO薄膜,X射线衍射(XRD)分析表明沉积温度在680℃以上可以实现 (400)取向生长,740℃薄膜可以实现cubic-on-cubic的方式外延生长.原子力显微镜(AFM)和扫描电子显微镜(SEM)分析分别显示CCTO薄膜的表面平整,界面清晰.后位的反射高能电子衍射(RHEED)观察到CCTO薄膜的电子衍射图谱,为点状.在MgO基片上,由于薄膜与基片较大的晶格失配,通过生长具有(100)和(110)取向的LaNiO3(LNO)缓冲层,诱导后续生长的CCTO薄膜随着温度的提高,由(220)取向生长转变成(220),(400)取向生长.     

Central metal effect on the organization of porphyrin LB films

Monolayers and Langmuir–Blodgett (LB) films of 5,10,15,20-tetra-4-oxy (2-stearic acid) phenylporphyrin (TSPP) and its complexes TSPPCu(II) and TSPPMn(III)Cl have been studied. π–A isotherms show that the molecular areas of the three molecules are similar to one another, while the polarized UV-vis spectra of the transferred films show different tilt angles of macrocycles with respect to the substrates: TSPP, 31°; TSPPCu(II), 0°; TSPPMn(III)Cl, 52°. The UV-vis spectra show that the π–π interactions between porphyrin macrocycles in monolayers of these three porphyrins are different. The Brewster angle microscopy (BAM) observations suggest that the monolayer behavior is also dependent on the central metal ions. These results indicate that the central metal ions have great influence on the organization of the films.     

Ordered porous diamond films fabricated by colloidal crystal templating

We have developed a colloidal crystal templating method for preparation of diamond films with 2D and 3D ordered porous structures. The technological process involved breaks down into (a) impregnation into the pores of silica colloidal crystal (opal) films of detonation nanodiamond (DND) particles from their hydrosol; (b) microwave plasma-enhanced chemical vapor deposition (MWPECVD) regrowth with diamond of pores with high DND filling; (c) Ar(+) ion dry etching of fragments of shells of coalesced diamond crystallites which form in the course of MWPECVD on the surface of the SiO(2) beads making up the outer surface of a film and (d) wet etching of the SiO(2) template in aqueous HF solution. The final samples are either connected to the substrate or free-standing films of various thicknesses having 2D or 3D ordered porous structures. The morphology of the diamond films fabricated by this method replicates the pore network of the opal template. Raman measurements confirm the diamond structure of the synthesized ordered porous material.     

Characterization of PZT thick films fabricated by micro-pen direct-writing

Lead zirconate titanate thick films have been deposited on platinum coated alumina substrates using micro-pen direct-writing technique. The viscosity, film thickness, interface, surface roughness, dielectric, and ferroelectric properties were investigated with different paste rheology, scanning speed and distance between lines. The results showed that in order to obtain good film, the viscosity values should below 10 Pa S in the writing range, and the proper writing speed should be kept at 4 mm/s, while the distance between lines should be kept as 300 μm. Comparing with the sample prepared by screen printing, the dielectric constant was increased from 710 to 750 and the dielectric loss was decreased from 0.015 to 0.012. Moreover, the two samples had similar ferroelectric properties with the remanent polarization P _r is 30 μC/cm² and the coercive field E _c is 18 kV/cm. These results mean that the Micro-pen writing is a very effective method to prepare thick films.     

Extremely-high-intensity photoluminescence from CuBr films fabricated by film-substrate chemical reaction of CuCl films on KBr-crystal substrate

High quality CuBr film is fabricated by film-substrate chemical reaction of CuCl on KBr, where CuCl is vacuum-deposited film of the order of ∼ 100 nm thickness and KBr is fleshly-cleaved single crystal. The resulting CuBr films show ∼ 10³ times higher efficiency of free-exciton photoluminescence (PL) than conventional CuBr films. The efficiency exceeds that of conventional CuCl films even by a factor of ∼ 10², despite the general recognition that the free-exciton PL from CuBr is much weaker than that from CuCl. The present result encourages us to challenge to rethink the exciton PL in CuBr as well as in CuCl, because the compounds are the model materials for basic and application studies of linear/nonlinear exciton-related PL properties of solids.     

Patterned structures fabricated on chalcogenide phase-change thin films by laser direct writing

In laser direct writing technology, the pattern is usually written in a photoresist. In this work, we use the chalcogenide phase change thin films as the laser direct writing materials, and patterned structures with different shapes and sizes were directly written with different laser wavelengths. Compared with traditional photoresist materials, the patterned structures can be directly formed in the chalcogenide phase change thin films without developing and etching procedures, and also can be directly written with different laser wavelengths. By tuning the laser parameters precisely, patterned structures with different sizes and shapes could be obtained as well. The analysis indicates that the formation mechanism of the patterned structure is mainly due to the volume expansion caused by material vaporization and the interior of the patterned structure is hollow with some solid leavings, and the chalcogenide phase change thin films are very good candidate materials for patterned structure formation.