基于SPM技术的纳米信息存储薄膜的研究进展

扫描探针显微技术SPM可以在原子或分子尺度上对表面进行表征和修饰，应用SPM技术可以在薄膜表面形成纳米级的信息点阵，特别适合发展超高密度的信息存储，是一种非常有希望代替传统磁存储，光存储的纳米级存储技术，本文介绍了纳米信息存储薄膜的研究进展，并对其制备技术和读写机制进行了初步的探讨。     

A method for the preparation of PMMA-SiO2 nanocomposites with high homogeneity

It is possible to optimize the performance of the inorganic-organic composites dispersing the inorganic component in the organic matrix on a nanomiter length scale. If dry the inorganic phase cannot be intimately dispersed during the incorporation in the matrix. When the particle surface is organically modified, and the incorporation is made starting from a liquid dispersion (particles in polymer solution), the resulting composites exhibit an excellent homogeneity. Here, monolithic [poly(methyl methacrylate)/monodisperse silica particles] nanocomposites have been prepared and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), micro-hardness, and differential scanning calorimetry (DSC).     

n-Al2O3/Ni复合镀层的组织与滑动磨损性能研究

用电刷镀技术制得了镍基n-Al2O3复合镀层，并对镀层的滑动磨损性能进行了试验研究。纳米复合镀层的表面形貌比较细腻，镀层中纳米粒子分布均匀，与基质金属结合紧密。镀层显微硬度达到HV700，比快速镍镀层提高约40％。滑动磨损试验结果表明，随着纳米粒子含量的增大，镀层的耐磨性提高，摩擦系数也呈增大趋势；但当镀层中n-Al2O3粒子的超过2.56%(质量分数）时，镀层的耐磨性显著下降。纳米复合镀层的磨损机制以疲劳磨损为主，而快速镍底层以粘着磨损为主。     

纳米4-H碳化硅薄膜的掺杂现象

对纳米晶SiC薄膜进行了P和B的掺杂,B掺杂效率比P高,其暗电导预前因子与激活能遵守Meyer-Neldel规则,并有反转Meyer-Neldel规则出现.掺杂效率比非晶态碳化硅薄膜高是纳米碳化硅薄膜的特点之一.非晶态中的隧穿和边界透射对输运有一定贡献.     

Sol-gel processing: A versatile concept for special glasses and ceramics

The various parameters related to sol-gel processing are discussed with special reference to those which usually attract less attention but depending on the final product in mind, can play important roles. The versatility of the sol-gel technique in materials preparation is demonstrated by discussing the various products developed at the author’s laboratory by using this processing method.     

纳米二氧化钛的表面修饰与应用的研究进展

介绍了纳米二氧化钛表面修饰的两种主要方法:无机和有机表面包覆,以及进行修饰后的纳米二氧化钛的应用.     

Oxygen Tracer Diffusion in Vitreous Silica

Oxygen diffusion in vitreous silica glass is studied using the gas exchange technique. The tracer concentration profiles are consistent with a model based on two mechanisms, one network and the other interstitial. These processes are coupled through limited network–interstitial exchange. Nuclear reaction analysis and secondary ion mass spectrometry techniques are performed and compared. These results are compared to experiments on transport in thin silica films grown on single-crystal silicon.     

A Silicon–Silica Nanocomposite Material

The synthesis and characterization of a novel silicon–silica nanocomposite material are reported. A self‐assembly method allows the encapsulation of silicon nanoclusters within the channels of a periodic mesoporous silica thin film. The result is the formation of a silicon–silica nanocomposite film with bright, room‐temperature photoluminescence in the visible range, and a nanosecond luminescence lifetime. The properties of the nanocomposite material have been studied by several analytical techniques, which collectively show the existence within the channels of non‐diamondoid‐structure‐type silicon nanoclusters with various hydrogenated silicon sites. It is estimated that the silicon nanoclusters in the silica mesoporous films occupy up to 39 % of the accessible pore volume. The nanocomposite film shows improved resistance to air oxidation compared to crystalline silicon. The high loading and chemical stability to oxidation under ambient conditions are important advantages in terms of the development of silicon‐based light‐emitting diodes from this class of materials.     

Growth and characterization of barium copper oxalate single crystals in gels

Barium copper oxalate was grown in silica hydrogel at ambient temperature. The effect of various parameters like gel pH, gel density, gel aging and concentrations of reactants on the growth of these crystals was studied. The crystals grown were characterized by chemical analysis, X-ray powder diffractometry, infrared spectroscopy, thermogravimetric and differential thermal analysis. The results of these observations are described and discussed.     

Periodic surface modeling for computer aided nano design

Current solid and surface modeling methods based on Euclidean geometry in traditional computer aided design are not efficient in constructing a large number of atoms and particles. In this paper, we propose a periodic surface model for computer aided nano design such that geometry of atoms and molecules can be constructed parametrically. At the molecular scale, periodicity of the model allows thousands of particles to be built efficiently. At the meso scale, inherent porosity of the model represents natural morphology of polymer and macromolecule. Surface and volume operations are defined to support crystal and molecular model creation with loci and foci periodic surfaces. The ultimate goal is to enable computer assisted material and system design at atomic, molecular, and meso scales.