共查询到19条相似文献,搜索用时 140 毫秒
1.
2.
3.
采用电化学沉积法,在氧化铝模板中成功制备了直径50nm的Fe纳米线的高度有序阵列。纳米线的结构和磁学特性分别用透射电子显微镜(TEM),扫描电子显微镜(SEM),X射线衍射仪(XRD)和振动样品磁力计(VSM)测试。结果表明,Fe纳米线是以fcc结构存在。当外加磁场与纳米线的线轴平行时,测得的矫顽力为21000e,剩磁比为0.89,而当外加磁场与纳米线线轴垂直时,所测得的矫顽力仅为1600e,剩磁比为0.2。这表明纳米线阵列具有明显的各向异性,纳柴癌的易妯方向为纳粜姥姥妯方向. 相似文献
4.
在氧化铝模板的纳米孔洞中,用电化学的方法沉积钴铁合金纳米线,经过550℃、30h氧化处理,成功制备出钴铁氧体纳米线阵列.分别用透射电子显微镜(TEM)、X射线衍射仪(XRD)和振动样品磁场计(VSM)对样品的形貌、晶体结构和磁学性质进行了表征测试.TEM观察结果显示纳米线粗细均匀,直径约为70nm.XRD显示纳米线的物相结构为CoFe2O4;VSM测试结果表明,CoFe2O4纳米线阵列的磁滞回线矫顽力为1.190×105A/m,比氧化处理前的钴铁合金纳米线阵列有显著提高. 相似文献
5.
Co88Ni12合金纳米线阵列的制备与磁性能表征 总被引:1,自引:0,他引:1
采用直流电化学沉积方法,在多孔阳极氧化铝模板的纳米级微孔内电沉积钴镍合金,制备出直径为30nm,长度为几个微米的准一维合金纳米线(阵列)材料;随后采用场发射扫描电子显微镜(FE-SEM),透射电子显微镜(TEM),X射线衍射仪(XRD),振动样品磁强计(VSM)对纳米线的形貌、结构及其磁性能进行了相关表征与测试.发现所制备的Co88Ni12合金纳米线表面光滑,粗细均一,具有较高的长径比;呈现密排六方结构(hcp),沿[100]择优取向生长,易磁化方向沿纳米线轴向方向. 相似文献
6.
7.
使用小孔径阳极氧化铝模板制备Fe0.3Co0.7纳米线有序阵列,研究了热处理对其磁性的影响.结果表明,热处理对Fe0.3Co0.7纳米线有序阵列的结晶度和局部形状各向异性有重大的影响,导致纳米阵列的矫顽力和剩磁比发生相应的变化.在适当热处理条件下获得的Fe0.3Co0.7纳米线有序阵列具有较高的矫顽力和剩磁比.在H2保护下550℃处理时获得最高的矫顽力2.63×105 A/m,矫顽力随着热处理时间的增加先是快速增加,然后趋向平缓,最后有一定程度的下降. 相似文献
8.
9.
使用电化学沉积方法,在有序的氧化铝模板(AAO)孔洞中制备了铁纳米线有序阵列.用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)、对样品的结构、形貌、进行表征和观测.XRD的结果表明所制备的样品为纯的立方面心铁.SEM的图片清晰地说明铁纳米线阵列是大面积、高填充率和高度有序的.TEM的结果显示纳米线直径均匀、表面光滑且长径比大.磁测量的结果表明纳米线阵列的易磁化轴是垂直于模板表面的。 相似文献
10.
采用溶胶-凝胶法制备了单相Bi0.95 Eu0.05Fe0.95 Co0.05 O3纳米粉末。用X射线衍射仪(XRD)和扫描电子显微镜(SEM)测量分析了其结构和形貌,结果表明样品仍为钙钛矿菱方结构。样品Fe2p的X射线吸收谱(XAS)表明样品中Fe的价态处于Fe2+和Fe3+的混合态。利用振动样品磁强计(VSM)测量样品的磁性特征,结果表明样品具有完整闭合的磁滞回线,表现出室温的铁磁性,相比BiFeO3样品磁性得到明显增强。 相似文献
11.
Fe3Co7 alloy nanowire arrays have been fabricated by direct current electrodeposition of Fe2+ and Co2+ into anodic aluminum oxide (AAO) templates. The phase structure and magnetic properties of the nanowires were studied by
transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and vibrating sample
magnetometer (VSM). Magnetic measurements show that the coercivity and remanence of the as-deposited Fe3Co7 Alloy nanowires increase dramatically after heat-treatment at 773 K for 2 h, and the nanowire arrays exhibit uniaxial magnetic
anisotropy with easy magnetization direction along the nanowire axes owing to the large shape anisotropy. The great difference
between practical coercivity and ideal coercivity was also discussed in detail. 相似文献
12.
Jian Yang Chunxiang Cui Wei Yang Bing Hu Jibing Sun 《Journal of Materials Science》2011,46(7):2379-2383
A new type of magnetic material, Fe7Co3 nanowires, was successfully synthesized for the first time via a simple electrodeposition method. Highly uniform, self-ordered
porous anodic aluminum oxide (AAO) membranes were prepared by the way of electrochemical. Fe7Co3 alloy nanowire arrays were fabricated in the porous alumina template in an aqueous solution of FeCl2 and CoCl2 by direct current electrodepositing. The microstructures of nanowires and AAO template were characterized by XRD, SEM, and
TEM. The results show that a single Fe7Co3 nanowire is 40 nm in width and 2.5 μm in length with a preferred crystal face (110) during growing. The Fe7Co3 nanowire arrays have uniaxial magnetic anisotropy with easy magnetization direction along the nanowire axis due to the large
shape anisotropy. It also shows that Fe7Co3 nanowire is a well-soft magnetic phase compared with Fe nanowires. It illustrates that Fe7Co3 possess higher saturation magnetization. 相似文献
13.
Zuxin Ye D. G. Naugle Wenhao Wu I. Lyuksyutov 《Journal of Superconductivity and Novel Magnetism》2010,23(6):1083-1085
Superconducting properties of a new ferro-magnet–superconductor hybrid structure have been investigated. Organized arrays
of Co nanowires are first electroplated into the columnar pores of anodic aluminum oxide (AAO) membranes. Superconducting
Pb/Bi (18 at.%) films are then quench-condensed onto the surface of the AAO membranes filled with Co nanowires. The Co nanowire
array produces a magnetic field with a strong spatial variation in the superconducting film. Hysteretic superconducting properties
and enhanced critical currents have been observed in applied external magnetic fields, which we explain based on the magnetic
domain structure of the Co nanowire arrays. 相似文献
14.
Ordered ZnO nanowire arrays embedded in anodic aluminum oxide (AAO) membranes were fabricated by electrochemical deposition of Zn(NO3)2 H3BO3 solution in a boiling bath. Scanning electron microscope (SEM) and transmission electron microscope (TEM) observation results show that the polycrystalline ZnO nanowires with diameters around 100 nm were uniformly assembled into the ordered nanochannels of the AAO. The results of the investigation into photoluminescence (PL) and electronic paramagnetic resonance (EPR) measurements reveal that the interfaces between the ZnO nanowires and the pore walls of the AAO create a lot of oxygen vacancies, which are responsible for the green light emission (peaking around 512 nm) and the huge enhancement of the PL emission. 相似文献
15.
Highly-ordered ternary Fe-Co-Ni alloy nanowire arrays with diameters of about 50 nm have been fabricated by alternating current (AC) electrodeposition into the nanochannels of porous anodic aluminum oxide templates. SEM and TEM results indicate that the alloy nanowires are highly ordered. XRD and HRTEM results show that the ternary FeCoNi alloy nanowires are polycrystalline, with HCP-FCC dual phase structure. Magnetic measurements demonstrate that the ternary alloy nanowire arrays have an obvious magnetic anisotropy with an easy magnetization direction being parallel to the nanowire arrays. Along the easy magnetization direction, the coercivity (H c ) and squareness ratio (S) increase as the annealing temperature increases, and reach a maximum level (H c = 1337 Oe, S = 0.96) at 300 °C. 相似文献
16.
Mingzai WU Lianzeng YAO Weili CAI Guowei JIANG Xiaoguang LI Zhen YAO)Department of Materials Science Engineering University of Science Technology of China Hefei China)Department of Physics University of Texas at Austin Austin TX - USA 《材料科学技术学报》2004,(1)
Ordered ZnO nanowire arrays embedded in anodic aluminum oxide (AAO) membranes were fabricated by electrochemical deposition of Zn(NO3)2+H3BO3 solution in a boiling bath. Scanning electron microscope (SEM) and transmission electron microscope (TEM) observation results show that the polycrystalline ZnO nanowires with diameters around 100 nm were uniformly assembled into the ordered nanochannels of the AAO. The results of the investigation into photoluminescence (PL) and electronic paramagnetic resonance (EPR) measurements reveal that the interfaces between the ZnO nanowires and the pore walls of the AAO create a lot of oxygen vacancies, which are responsible for the green light emission (peaking around 512 nm) and the huge enhancement of the PL emission. 相似文献
17.
Park DJ Kim SH Lee KJ Lee JH Choa YH 《Journal of nanoscience and nanotechnology》2006,6(11):3408-3411
High-density and uniform-sized FeCo alloy nanowires were prepared by electro deposition of Fe2+ and Co2+ into Anodic aluminum oxide (AAO) templates with two different diameters. These templates were fabricated with three-step anodization method. The additional anodization after the 2nd anodization step resulted in the decrease of the thickness of bottom barrier layer. It found an optimum condition to obtain a successful electrodeposition of Fe2+ and Co2+ into AAO templates. The nanowires with the diameters of 25 nm and 80 nm were homogeneously embedded in the AAO templates and their magnetic properties were strongly affected by diameters of nanowire. 相似文献
18.
Erhong YUE) Gang YU+) Yuejun OUYANG) Baicheng WENG) Weiwei SI) Liyuan YE) ) State Key Laboratory of Chemo/Biosensing Chemometrics Hunan University Changsha China ) 《材料科学技术学报》2008,24(6):850-856
The synthesis of Pd-Ag alloy nanowires in nanopores of porous anodic aluminum oxide (AAO) template by electrochemical deposition technique was reported. Pd-Ag alloy nanowires with 16%-25% Ag content are expected to serve as candidates of useful nanomaterials for the hydrogen sensors. Scanning electron microscopy (SEM) and energy dispersed X-ray spectroscopy (EDX) were employed to characterize the morphologies and compositions of the Pd-Ag nanowires. X-ray diffraction (XRD) was used to characterize the phase properties of the Pd-Ag nanowires. Pd-Ag alloy nanowire arrays with 17.28%-23.76% Ag content have been successfully fabricated by applying potentials ranging from -0.8 to -1.0 V (vs SCE). The sizes of the alloy nanowires are in agreement with the diameter of AAO nanopores. The underpotential deposition of Ag+ on Pd and Au plays an important role in producing an exceptionally high Ag content in the alloy. Alloy compositions can still be controlled by adjusting the ion concentration ratio of Pd^2+ and Ag+ and the electrodeposition processes. XRD shows that nanowires obtained are in the form of alloy of Pd and Ag. 相似文献
19.
Fe-doped ZnO dilute magnetic semiconductor (DMS) nanowire arrays were fabricated in anodic aluminum oxide (AAO) membranes using electro-codeposition followed by long-time anneal process. The morphology, chemical composition and crystal structure were characterized by field emission scanning electron microscope (FE-SEM), high resolution transmission electron microscope (HRTEM) equipped with an energy dispersive x-ray spectrometer, and X-ray diffraction (XRD) spectroscopy. The results prove that the Fe has been successfully doped in the lattice of ZnO nanowire arrays and the estimated Fe atomic ratio is around 22%. Micro-superconducting quantum interference device (SQUID) shows that the nanowire arrays exhibit room temperature (300 K) ferromagnetic and anisotropic ferromagnetic behavior which may be a consequence of the easy magnetization direction along the wire axes and magnetostatic interaction. 相似文献