磁控溅射制备Co1-xPtx:C复合纳米颗粒薄膜的研究

采用组合靶，利用磁控共溅射技术制备了Co1-xPtx：C复合纳米颗粒薄膜，并从实验和理论上对不同Pt浓度CoPt：C薄膜的组分、微结构、磁性能、组分和微结构与磁性能之间的关系以及薄膜的应用进行了初步研究。发现CoPt粒子取向和磁性能与CoPt：C薄膜中的Pt浓度有密切关系，在较高Pt浓度的CoPt：C薄膜中观察到垂直各向异性现象。通过改变Pt浓度，可以获得粒子粒径小于10nm、矫顽力可控、垂直磁晶各向异性较高的薄膜。晶格结构和晶粒之间的作用力可认为是影响CoPt：C薄膜磁性能的主要因素。     

宁波材料所在硬磁纳米颗粒的绿色和宏量制备方面取得进展CSCD

磁性纳米颗粒在催化、生物医用、磁记录以及高性能永磁体等领域都具有重要的应用前景。在这些应用以及相关研究中,纳米颗粒的尺寸、形貌对磁性及其相关性能影响至关重要,因此如何探索出一种简便的纳米颗粒的合成方法具有重要意义。在各种磁性纳米材料中,     

碳纳米材料在导热聚合物复合材料中的应用

介绍了三种具有较高热导率的碳纳米材料:碳纳米管、纳米石墨片及纳米碳纤维的结构与导热性能,概述了三种碳纳米材料在改善聚合物复合材料导热性能方面的应用,重点分析了碳纳米材料的种类、用量、表面改性方法及复合材料的制备方法对聚合物复合材料热导率的影响,并对含碳纳米材料的导热聚合物复合材料未来的发展方向进行了分析与展望。     

纳米磁性材料

纳米磁性材料是指材料尺寸线度在纳米级(1～100nm)的准零维超细微粉,二维超薄膜或一维超细纤维(丝)或由它们组成的固态或液态磁性材料。 纳米磁性材料是纳米材料的一个重要门类,所以除在物理、化学方面具有纳米材料的介观(即介于宏观与微观分子、原子之间)特性外,还具有其特殊的磁性能一介观磁性,表现为:量子尺寸效应、超顺磁性、宏观     

在扫描电子显微镜中原位操纵、加工和测量纳米结构

在电子显微镜中对纳米材料和纳米结构进行原位测量是了解纳米材料的结构与性能关系的最重要手段,并且,在电子显微镜中操纵和加工纳米材料与纳米结构还可研究新结构和新器件.由于扫描电镜有大的样品室、可较容易地引入多个多种测量和操纵探针、并可配备多种探测器从多个角度对同一个样品进行表征,使得扫描电镜中的原位研究在纳米材料和纳米器件...     

荧光磁性纳米复合物及其制备方法和应用

本发明的荧光磁性纳米复合物及其制备方法和应用属纳米材料领域。以单个磁性纳米粒子为核，核外逐层包覆聚电解质多层膜、磁性纳米粒子和聚电解质多层膜、半导体荧光纳米晶和聚电解质多层膜；所述的聚电解质多层膜为聚阳离子电解质和聚阴离子电解质相间包覆的1-30层。经吸附聚电解质-吸附磁性纳米粒子-吸附半导体荧光纳米晶的过程制备。     

宁波材料所在硬磁纳米颗粒的绿色和宏量制备方面取得进展

<正>磁性纳米颗粒在催化、生物医用、磁记录以及高性能永磁体等领域都具有重要的应用前景。在这些应用以及相关研究中,纳米颗粒的尺寸、形貌对磁性及其相关性能影响至关重要,因此如何探索出一种简便的纳米颗粒的合成方法具有重要意义。在各种磁性纳米材料中,化学有序的L1_0结构的Co(Fe)Pt纳米颗粒由于具     

纳米氧化物光谱特性及其相关机理的初步分析

纳米氧化物粉体与常规氧化物粉体相比呈现出吸收峰发生红移、蓝移等特异性能。初步研究表明,纳米颗粒尺寸越小,这些特异效应越明显,有关纳米氧化物光谱特性的研究已成为当前纳米材料研究的热点之一;然而,其光谱特性机理尚无统一解释。通过对波谱吸收机理和纳米材料特性的综合考察和分析,以及结合具体纳米氧化物材料的讨论,给出了导致蓝移、红移的主要因素。     

名词释义——准一维纳米材料

准一维纳米材料是指在两维方向上为纳米尺度，长度为宏观尺度的新型纳米材料。如纳米棒、纳米线、半导体纳米量子线、纳米线阵列等都属于准一维纳米材料。这些新型材料的实验研究，为进一步研究纳米结构和准一维纳米材料的性能，建立准一维纳米材料的新理论和推进它们在纳米结构器件中的应用奠定了基础。     

磁性纳米材料及其在癌症诊疗中的应用

磁性纳米材料在不同的尺寸下分别呈现出铁磁性和超顺磁性。介绍了不同形式和用途的磁性纳米材料,包括磁性纳米颗粒、磁性脂质体、磁流体、铁磁微晶玻璃、碳铁复合物、超顺磁性氧化铁等,并对近年来磁性纳米材料在磁共振成像、肿瘤细胞分离、肿瘤靶向热疗、栓塞治疗及药物磁导向方面的应用进行了综述。总结了磁性纳米材料在癌症诊断及治疗中的作用和面临的困难,并对磁性纳米材料在深部肿瘤的诊断及癌症的联合治疗、基因治疗等应用方向进行了展望。     

Developing Biotemplated Data Storage: Room Temperature Biomineralization of L10 CoPt Magnetic Nanoparticles

L1₀ cobalt platinum can be used to record data at approximately sixfold higher densities than it is possible to on existing hard disks. Currently, fabricating L1₀ CoPt requires high temperatures (≈500 °C) and expensive equipment. One ecological alternative is to exploit biomolecules that template nanomaterials at ambient temperatures. Here, it is demonstrated that a dual affinity peptide (DAP) can be used to biotemplate L1₀ CoPt onto a surface at room temperature from an aqueous solution. One part of the peptide nucleates and controls the growth of CoPt nanoparticles from solution, and the other part binds to SiO₂. A native silicon oxide surface is functionalized with a high loading of the DAP using microcontact printing. The DAP biotemplates a monolayer of uniformly sized and shaped nanoparticles when immobilized on the silicon surface. X‐ray diffraction shows that the biotemplated nanoparticles have the L1₀ CoPt crystal structure, and magnetic measurements reveal stable, multiparticle zones of interaction, similar to those seen in perpendicular recording media. This is the first time that the L1₀ phase of CoPt has been formed without high temperature/vacuum treatment (e.g., annealing or sputtering) and offers a significant advancement toward developing environmentally friendly, biotemplated materials for use in data storage.     

Purely Electrical Controllable Complete Spin Logic in a Single Magnetic Heterojunction

Fully electrical manipulation of magnetism, preferably through spin current, is highly desired to achieve energy-efficient, nonvolatile, and programmable spin logic devices. It is demonstrated in this study that in a single Pt/IrMn/Co/Ru/CoPt heterojunction, all 16 Boolean logic functions can be realized in a purely electrical way, relying on electrical manipulation of magnetic-field-free spin-orbit torque (SOT) switching. By applying current pulses along with two orthogonal directions, the exchange bias between IrMn and Co, and the SOT switching polarity (clockwise or counterclockwise) of perpendicularly magnetized CoPt, can be reversibly controlled, enabling complete spin logic within a single nonvolatile memory. This study makes a significant step towards practical electrical programmable spin logic devices.     

Quantitative Recovery of Magnetic Nanoparticles from Flowing Blood: Trace Analysis and the Role of Magnetization

Magnetic nanomaterials find increasing application as separation agents to rapidly isolate target compounds from complex biological media (i.e., blood purification). The responsiveness of the used materials to external magnetic fields (i.e., their saturation magnetization) is one of the most critical parameters for a fast and thorough separation. In the present study, magnetite (Fe₃O₄) and non‐oxidic cementite (Fe₃C) based carbon‐coated nanomagnets are characterized in detail and compared regarding their separation behavior from human whole blood. A quantification approach for iron‐based nanomaterials in biological samples with strong matrix effects (here, salts in blood) based on platinum spiking is shown. Both materials are functionalized with polyethyleneglycol (PEG) to improve cytocompatibility (confirmed by cell toxicity tests) and dispersability. The separation performance is tested in two setups, namely under stationary and different flow‐conditions using fresh human blood. The results reveal a superior separation behavior of the cementite based nanomagnets and strongly suggest the use of nanomaterials with high saturation magnetizations for magnetic retention under common blood flow conditions such as in veins.     

Biologically Inspired and Magnetically Recoverable Copper Porphyrinic Catalysts: A Greener Approach for Oxidation of Hydrocarbons with Molecular Oxygen

An efficient synthetic method for magnetically recoverable hybrid copper porphyrinic nanomaterials is reported. These functionalized magnetic materials prove to be efficient bioinspired oxidation catalysts of olefins and thiols, using molecular oxygen as oxidant, in total absence of reductants and solvents, with the highest TON (turnover number) yet achieved for this reaction (≈200 000). A comparative study between homogeneous and heterogeneous oxidation of cyclohexene is discussed, revealing the heterogeneous system to be the most promising concerning stability and reusability of the catalysts. The full characterization of the magnetic hybrid porphyrinic nanomaterials, by transmission electron microscopy, flame atomic absorption spectrometry, thermogravimetry, N₂ sorption, and infrared spectroscopy, is also described.     

Nanostructures, magnetic semiconductors and spintronics

The aim of this paper is to give a brief overview of recent advances in the area of semiconductor nanomaterials, which represent extremely promising applications for materials with the spin-polarized transport of the charge carriers. It is shown on the basis of the last theoretical and experimental achievements that the development of diluted semiconductors with the controlled disorder and the wide energy gaps as well as the study of their molecular structures are very prospective routes for producing of novel magnetic semiconductors.     

Microstructures in CoPtC magnetic thin films studied by superpositioning of micro-electron diffraction

Cross-sectional transmission electron microscopy observation of CoPtC thin films showed that 10 nm sized ultrafine particles of CoPt typically were elongated along the substrate normal. Analysis of the superposition of 40 micro-electron diffraction patterns showed that there was no preferred crystal orientation of CoPt particles. This superpositioning technique can be applied to thin films, whose X-ray diffraction analysis is difficult due to the small size of the crystals.     

一维纳米材料排列方法的研究进展

基于国内外一维纳米材料器件的最新研究进展,系统综述了近年来一维纳米材料的排列方法,并介绍了磁场排列法、电场排列法、微流法、Langmiur-Blodgett等方法的原理和优缺点。同时,指出了一维纳米材料器件集成所面临的挑战,例如无法兼顾大规模有序排列与单一纳米材料精确定位排列等。最后,简单展望了一维纳米材料排列方法的发展趋势,传统排列方法,包括磁学方法和电学方法等的发展已经遇到了技术瓶颈,短时间内难以得到本质性的优化,生物技术也许会成为一维纳米材料有序排列的一个发展方向。     

二维纳米材料磁性探测的双臂微悬臂梁设计

磁共振弱力探测技术能够对物质实现非破坏性的高精度结构信息探测,在物理、生物、医学等领域有着非常重要的应用。该技术中,超灵敏悬臂梁是实现弱力探测的核心组成之一。近年来,二维纳米材料由于其奇特的物理特性得到了越来越多的关注。为实现对二维纳米材料磁性的探测,基于单臂微悬臂梁模型,利用差动放大的方法,提出了双臂微悬臂梁的设计,并分析了双臂微悬臂梁中上下球形磁探针内外部的磁场分布,最后以单晶硅悬臂梁和钐钴合金磁球探针为例,对该悬臂梁进行数值模拟,发现该方案能够显著提高悬臂梁的探测灵敏度。     

飞秒激光组装一维纳米材料及其应用

一维纳米材料具有众多优异的特性,是构建微纳米功能性器件的基石。实现一维纳米材料在二维和三维空间的高精度和高定向组装是充分发挥其应用潜力的关键,同时也是制造难点。在众多纳米材料组装技术中,飞秒激光直写诱导组装技术具有独特优势,可实现一维纳米材料在任意三维结构中的可设计、高定向及高精度的组装。首先简要介绍了一维纳米材料组装研究的背景,并总结了非激光直写组装技术的研究现状和存在的挑战,然后较详细介绍了飞秒激光直写技术在一维纳米材料组装研究中的进展,重点回顾了金属(包括Au和Ag纳米线)、半导体(包括CNTs和ZnO)一维纳米材料的飞秒激光直写组装及微纳光电子功能器件的制造。并讨论了诱导一维纳米材料定向排布的光学力和非光学力(包括剪切力、体积收缩应力和空间限制)的作用机理,理论计算和实验研究结果验证了飞秒激光诱导的非光学力作用是导致一维纳米材料定向排布的主要原因。最后探讨了目前飞秒激光组装技术面临的一些问题和未来在高精度纳米材料组装和三维功能器件集成方面的发展趋势。