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用二次阳极氧化法制备了多孔氧化铝膜,并以之为模板,用直流电沉积法成功地将Co金属组装入多孔氧化铝膜的纳米孔洞中,观察与测试了Co—氧化铝纳米阵列结构和磁性。结果发现,二次阳极氧化法在短时间内就能制备出较为有序的多孔氧化铝膜;Co—氧化铝纳米阵列中的Co金属纳米线有一定的结晶择优取向,并且当多孔氧化铝模板的孔径减小,择优取向发生优化;Co—氧化铝纳米阵列有明显的磁各向异性。 相似文献
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一维纳米材料具有优良的尺寸效应,一维贵金属材料表现出不同于相应块体材料的特殊物理化学性能。本文以一维贵金属纳米结构的合成方法和机理为探讨重点,总结了近年来国内外用于控制合成一维贵金属纳米材料的主要方法,包括模板法、多元醇还原法、化学电沉积法以及金属催化还原法。着重以金属银、钯为例,介绍了其形状可控的一维纳米结构的生长机理,并以金、银等一维纳米材料为例介绍了其一维纳米结构在功能材料以及生物医学等领域的应用前景。指出建立一维金属纳米结构制备科学的新理论、新方法及其成核生长动力学模型是进一步研究的方向。 相似文献
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《陶瓷研究与职业教育》1999,(3)
纳米材料的特殊结构使它产生出四大效应:小尺寸效应、量子效应(宏观量子隧道效应)、表面效应和界面效应,从而具有传统材料所不具备的物理、化学特性。如TIOZ纳米陶瓷在常温下有奇特的韧性,在180“C温度时经受弯曲不断裂;CaFz纳米材料的塑性在80-180”C温度下提高100%.英国著名的材料专家Cahn称:这是解决陶瓷脆性的战略突破,使材料科学家们奋斗了近一个世纪的梦想成真。纳米金属的熔点比普通金属低几百摄氏度,气体在纳米材料中的扩散速度比通过一般材料快几千倍;纳米磁性材料的磁记录密度可比普通的提高10倍;纳米复合材料… 相似文献
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一维纳米材料因其特殊结构引起的新奇的物理和化学性质以及诱人的应用前景而备受关注.已经发展了多种制备一维纳米材料的方法,其中,模板法是一种制备纳米线阵列的常用方法,这种方法已经被成功地用于多种材料纳米线阵列的制备.金属离子辅助的溶液刻蚀方法可以在温和反应条件下大规模制备Si纳米线阵列,是一种重要的制备Si 相似文献
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用交流电化学沉积方法,在多孔铝阳极氧化膜的柱形孔内制备直径约60 nm,长度约为9.7 μm的Fe21Ni79合金纳米线.采用扫描电镜、透射电镜、X射线衍射仪和振动样品磁强计对纳米线的形貌 、结构和磁学性质进行了测试.结果表明,Fe21Ni79纳米线排列有序,长径比可控,合金呈fcc结构.当将其在外磁场下进行垂直磁化时,磁滞回线出现较高的矩形比0.86,矫顽力达1203Oe.且随着退火温度升高,矫顽力迅速增大,500℃时达到最大值1315Oe,之后又随退火温度的升高而下降.矩形比也呈现类似的变化规律. 相似文献
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采用两步法在FTO导电玻璃衬底上制备ZnO纳米棒,首先利用浸渍-提拉法在FTO导电玻璃衬底上制备ZnO晶种层,然后把有ZnO晶种层的FTO衬底放入盛有生长溶液的反应釜中利用水热法制备ZnO纳米棒.研究了生长溶液的浓度、生长温度和生长时间对所制备的对ZnO纳米棒阵列的微结构和光致发光性能的影响,利用X射线衍射(XRD)、扫描电子显微镜(SEM)和光致发光谱(PL)研究了ZnO样品的结构、形貌和光学性质.实验结果表明:所制备的ZnO纳米棒呈现六方纤锌矿结构,沿(002)晶面择优取向生长,纳米棒的平均直径约为100 nm,长度约为2.5 μm.所制备的ZnO纳米棒在390 nm附近具有很强的紫外发光峰和在550 nm附近有较弱的宽绿光发光峰. 相似文献
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To reduce irreversible capacity and improve cycle performance of tin used in lithium ion batteries, Sn–Ni alloy nanorod electrodes with different Sn/Ni ratios were prepared by an anodic aluminum oxide template-assisted electrodeposition method. The structural and electrochemical performance of the electrode were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, cyclic voltammetry, and galvanostatic charge–discharge cycling measurement. The results showed that the copper substrate is covered with uniformly distributed Sn–Ni alloy nanorods with an average diameter of 250 nm. Different phases (Sn, Ni3Sn4 and metastable phases) of alloy nanorod formed in the electrodeposition baths with different compositions of Sn2+ and Ni2+ ions. Sn–Ni alloy nanorod electrode delivered excellent capacity retention and rate performance. 相似文献
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H. Wang Z. P. Zhang X. N. Wang Q. Mo Y. Wang J. H. Zhu H. B. Wang F. J. Yang Y. Jiang 《Nanoscale research letters》2008,3(9):309-314
By thermal evaporation of pure ZnO powders, high-density vertical-aligned ZnO nanorod arrays with diameter ranged in 80–250 nm
were successfully synthesized on Si substrates covered with ZnO seed layers. It was revealed that the morphology, orientation,
crystal, and optical quality of the ZnO nanorod arrays highly depend on the crystal quality of ZnO seed layers, which was
confirmed by the characterizations of field-emission scanning electron microscopy, X-ray diffraction, transmission electron
microscopy, and photoluminescence measurements. For ZnO seed layer with wurtzite structure, the ZnO nanorods grew exactly
normal to the substrate with perfect wurtzite structure, strong near-band-edge emission, and neglectable deep-level emission.
The nanorods synthesized on the polycrystalline ZnO seed layer presented random orientation, wide diameter, and weak deep-level
emission. This article provides a C-free and Au-free method for large-scale synthesis of vertical-aligned ZnO nanorod arrays
by controlling the crystal quality of the seed layer. 相似文献
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Victor M Prida Javier García Lucia Iglesias Victor Vega Detlef G?rlitz Kornelius Nielsch Enrique Díaz Barriga-Castro Raquel Mendoza-Reséndez Arturo Ponce Carlos Luna 《Nanoscale research letters》2013,8(1):263
Highly hexagonally ordered hard anodic aluminum oxide membranes, which have been modified by a thin cover layer of SiO2 deposited by atomic layer deposition method, were used as templates for the synthesis of electrodeposited magnetic Co-Ni nanowire arrays having diameters of around 180 to 200 nm and made of tens of segments with alternating compositions of Co54Ni46 and Co85Ni15. Each Co-Ni single segment has a mean length of around 290 nm for the Co54Ni46 alloy, whereas the length of the Co85Ni15 segments was around 430 nm. The composition and crystalline structure of each Co-Ni nanowire segment were determined by transmission electron microscopy and selected area electron diffraction techniques. The employed single-bath electrochemical nanowire growth method allows for tuning both the composition and crystalline structure of each individual Co-Ni segment. The room temperature magnetic behavior of the multisegmented Co-Ni nanowire arrays is also studied and correlated with their structural and morphological properties. 相似文献
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Francisco Solís-Pomar Eduardo Martínez Manuel F Meléndrez Eduardo Pérez-Tijerina 《Nanoscale research letters》2011,6(1):524
A hydrothermal method to grow vertical-aligned ZnO nanorod arrays on ZnO films obtained by atomic layer deposition (ALD) is presented. The growth of ZnO nanorods is studied as function of the crystallographic orientation of the ZnO films deposited on silicon (100) substrates. Different thicknesses of ZnO films around 40 to 180 nm were obtained and characterized before carrying out the growth process by hydrothermal methods. A textured ZnO layer with preferential direction in the normal c-axes is formed on substrates by the decomposition of diethylzinc to provide nucleation sites for vertical nanorod growth. Crystallographic orientation of the ZnO nanorods and ZnO-ALD films was determined by X-ray diffraction analysis. Composition, morphologies, length, size, and diameter of the nanorods were studied using a scanning electron microscope and energy dispersed x-ray spectroscopy analyses. In this work, it is demonstrated that crystallinity of the ZnO-ALD films plays an important role in the vertical-aligned ZnO nanorod growth. The nanorod arrays synthesized in solution had a diameter, length, density, and orientation desirable for a potential application as photosensitive materials in the manufacture of semiconductor-polymer solar cells.
PACS
61.46.Hk, Nanocrystals; 61.46.Km, Structure of nanowires and nanorods; 81.07.Gf, Nanowires; 81.15.Gh, Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.) 相似文献17.
Hydrothermal synthesis and rate capacity studies of Li3V2(PO4)3 nanorods as cathode material for lithium-ion batteries 总被引:1,自引:0,他引:1
It is an effective method by synthesizing one-dimensional nanostructure to improve the rate performances of cathode materials for Li-ion batteries. In this paper, Li3V2(PO4)3 nanorods were successfully prepared by hydrothermal reaction method. The structure, composition and shape of the prepared were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scan electron microscope (SEM) and transmission electron microscope (TEM), respectively. The data indicate the as-synthesis powders are defect-rich nanorods and the sizes are the length of several hundreds of nanometers to 1 μm and the diameter of about 60 nm. The preferential growth direction of the prepared material was the [1 2 0]. The electrodes consisting of the Li3V2(PO4)3 nanorods show the better discharge capacities at high rates over a potential range of 3.0-4.6 V. These results can be attributed to the shorter distance of electron transport and the fact that ion diffusion in the electrode material is limited by the nanorod radius. All these results indicate that the resulting Li3V2(PO4)3 nanorods are promising cathode materials in lithium-ion batteries. 相似文献
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In this work, ZnO nanorod arrays were grown on glass substrate by the wet chemical method, and the effect of synthesis temperature on the properties was investigated. The grown nanorods were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Raman and Photoluminescence (PL) measurements. XRD pattern showed that nanorod prepared at 80 °C and 90 °C has high crystallinity with wurtzite structure and orientated along the c-axis. However, nanorods were not formed at 60 °C and 70 °C due to less energy supply for the growth of the ZnO. FE-SEM results showed that the morphology and the size of ZnO can be effectively controlled. In particular, as the temperature increased, diameter of the nanorod was increased while length decreased. Raman scattering spectra of ZnO nanorod arrays revealed the characteristic E2high mode that is related to the vibration of oxygen atoms in the wurtzite ZnO. Room-temperature PL spectra of the ZnO nanorods revealed a near-band-edge (NBE) emission peak. The NBE (UV light emission) band at ~383 nm might be attributed to the recombination of free exciton. The narrow full-width at half-maximum (FWHM) of the UV emission indicated that ZnO nanorods had high crystallinity. 相似文献
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J. Volk T. Nagata R. Erdélyi I. Bársony A. L. Tóth I. E. Lukács Zs. Czigány H. Tomimoto Y. Shingaya T. Chikyow 《Nanoscale research letters》2009,4(7):699-704
Highly uniform and c-axis-aligned ZnO nanorod arrays were fabricated in predefined patterns by a low temperature homoepitaxial
aqueous chemical method. The nucleation seed patterns were realized in polymer and in metal thin films, resulting in, all-ZnO
and bottom-contacted structures, respectively. Both of them show excellent geometrical uniformity: the cross-sectional uniformity
according to the scanning electron micrographs across the array is lower than 2%. The diameter of the hexagonal prism-shaped
nanorods can be set in the range of 90–170 nm while their typical length achievable is 0.5–2.3 μm. The effect of the surface
polarity was also examined, however, no significant difference was found between the arrays grown on Zn-terminated and on
O-terminated face of the ZnO single crystal. The transmission electron microscopy observation revealed the single crystalline
nature of the nanorods. The current–voltage characteristics taken on an individual nanorod contacted by a Au-coated atomic
force microscope tip reflected Schottky-type behavior. The geometrical uniformity, the designable pattern, and the electrical
properties make the presented nanorod arrays ideal candidates to be used in ZnO-based DC nanogenerator and in next-generation
integrated piezoelectric nano-electromechanical systems (NEMS). 相似文献