共查询到18条相似文献,搜索用时 906 毫秒
1.
采用交替沉积磁控溅射工艺制备了超薄多层的FeCoB SiO2 磁性纳米颗粒膜 .利用x射线衍射仪、扫描探针显微镜、透射电子显微镜分析了薄膜的微结构和形貌特征 .采用振动样品磁强计、四探针法、微波矢量分析仪及谐振腔法测量薄膜试样的磁电性能和微波复磁导率 .重点对SiO2 介质相含量、薄膜微结构对电磁性能产生重要影响的机理做了分析和探讨 .结果表明 :这类FeCoB SiO2 磁性纳米颗粒膜具有良好的软磁性能和高频电磁性能 ,2GHz时的磁导率 μ′高于 70 ,可以应用于高频微磁器件或微波吸收材料的设计 相似文献
2.
采用直流/射频磁控溅射方法和不连续多层交替沉积工艺,制备了CoFeB/MgO系列纳米不连续多层薄膜,研究了微波频段下的电磁性能.结果表明,通过调整CoFeB合金相和MgO介质相的相对含量可有效调控薄膜的微结构和电磁性能,且在[Co64Fe24B12(0.7nm)/MgO(0.4nm)]40薄膜中获得了优良的微波软磁性能和高电阻率,其饱和磁化强度1.3 T,难轴矫顽力130 A/m,电阻率3.4mΩ·cm,且共振频率高达2.1 GHz,磁导率实部μ′和虚部μ″在1.59 GHz处均高于240,并且在0.9—2 GHz宽频带范围同时大于100.该薄膜可用于微波吸收材料和电磁兼容的设计中.
关键词:
纳米磁性颗粒膜
磁导率频谱
电磁性能
吸波材料 相似文献
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用射频磁控溅射法制备了金属/半导体Fex(In2O3)1-x颗粒膜,研究了该系列颗粒膜的微结构和磁性.实验结果表明:纳米尺度的Fe颗粒均匀地分散在非晶体态In2O3中.室温下样品具有超顺磁性,符合朗之万方程. 相似文献
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利用直流对靶磁控溅射技术在单晶Si衬底上制备了C/CoCrTa/X (X=Cr,Ti)介质材料.分别采用振动样品磁强计、X射线衍射仪、扫描探针显微镜对样品的磁性、微结构等进行了测试分析.研究发现,Ti缓冲层有利于样品中Co晶粒的易轴垂直于膜面生长.以Ti为缓冲层的样品,颗粒尺寸和表面粗糙度较小,而且磁畴明显,说明以Ti为缓冲层的薄膜样品更适宜做垂直磁记录.
关键词:
CoCrTa
垂直磁记录
缓冲层
微结构 相似文献
8.
β-FeSi2作为一种环境友好的半导体材料,颗粒化及非晶化正在成为提高其应用性能和改善薄膜质量、膜基界面失配度的有效途径.利用射频磁控溅射法在单晶Si基体上沉积Fe/Si多层膜,合成纳米β-FeSi2/Si多层结构.通过透射电子显微镜、高分辨电子显微术等分析手段,研究了多层结构和制备工艺之间的相互关系.研究结果表明,采用磁控溅射Fe/Si多层膜的方法,不需要退火就可以直接沉积得到β-FeSi2相小颗粒.β-FeSi2相
关键词:
2')" href="#">β-FeSi2
磁控溅射
透射电子显微镜
半导体薄膜 相似文献
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用射频磁控共溅射法制备了Cu体积分数分别为10%,15%,20%和30%的Cu-MgF2复 合金属陶 瓷薄膜.用x射线衍射、x射线光电子能谱和变温四引线技术对薄膜的微结构、组分及电导特 性进行了测试分析.微结构分析表明:制备的Cu-MgF2复合薄膜由fcc-Cu晶态纳 米微粒镶嵌 于主要为非晶态的MgF2陶瓷基体中构成,Cu晶粒的平均晶粒尺寸随组分增加从1 1.9nm增 至17.8nm.50—300K温度范围内的电导测试结果表明:当Cu体积
关键词:
2复合纳米金属陶瓷膜')" href="#">Cu-MgF2复合纳米金属陶瓷膜
微结构
组分
电导特性
激活能
渗透阈 相似文献
10.
通过射频磁控溅射法制备了Fe_Si_B_Nb_Cu薄膜,采用x射线衍射与Mssb auer谱相结合分析了薄膜的微结构形态,研究了不同溅射功率对薄膜微结构的影响.其结果 表明:在较低溅射功率密度下,薄膜为无定型结构;随着溅射功率密度升高,沉积薄膜无需 热处理,便呈现出晶态和非晶态的混合相结构,晶态为纳米级的α_Fe(Si)和α_Fe(B)固溶 体;α_Fe(Si)相和α_Fe(B)相的体积分数、微结构组态、磁矩取向及宏观磁性能均随着溅 射功率的变化而变化.
关键词:
溅射功率
Fe_Si_B_Nb_Cu合金
薄膜微结构
磁矩取向 相似文献
11.
Lidong Liu Shunhua Liu Liyang Chen Jingbo Guo 《Journal of magnetism and magnetic materials》2010,322(13):1736-1740
To solve more and more serious electromagnetic interference problem, one thin microwave absorbing sheet employing carbonyl-iron powder (CIP) and chlorinated polyethylene (CPE) was prepared. The pattern, static magnetic properties and phase of CIP were characterized by scanning electron microscope (SEM), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD), respectively. The electromagnetic parameters of CIP were measured in the frequency range of 2-18 GHz, and the electromagnetic loss mechanisms of the powder were discussed. The microwave absorption properties of composite sheets with different thicknesses and CIP ratios in matrix were investigated by measuring reflection loss (RL) in 2-18 GHz frequency range using the arch method. The results showed that appropriate CIP content and thickness could greatly improve microwave absorption properties in lower frequency range. For the sample with the weight ratio (CIP:CPE) of 16:1 and 1.5 mm thickness, the bandwidth (RL below −10 dB) achieved 1.1 GHz (2-3.1 GHz), and the minimum reflection loss value was obtained −13.2 dB at 2.2 GHz. This suggested that CIP/CPE composites could be applied as thin microwave absorbers in S-band (2-4 GHz). 相似文献
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A novel scanning-probe setup is reported that maps the complex transmission of microwaves. Response to topographic features as small as 15 nm was observed. The sharpened coaxial probe tip serves as a microwave antenna and, at the same time, as a tunnel tip to warrant precise distance control by STM (scanning tunneling microscope) feedback. The instrument can be applied to map the microwave conductivity of, e.g. thin films or low-dimensional semiconductors. Consequences for the development of an infrared microscope are outlined. 相似文献
13.
We report the observation of a propounced peak in surface resistance at microwave frequencies of 4.88 GHz and 9.55 GHz and
its disappearance after irradiation with swift ions in laser ablated DyBa2Cu3O7-δ (DBCO) thin films. The measurements were carried out in zero field as well as in the presence of magnetic fields (up to 0.8
T). The films were irradiated using 90 MeV oxygen ions at Nuclear Science Centre, New Delhi at a fluence of 3×1013 ions/cm2. Introduction of point defects and extended defects after irradiation suppresses the peak at 9.55 GHz whereas no suppression
is observed at 4.88 GHz. These results and the vortex dynamics in the films at microwave frequencies before and after irradiation
are discussed. 相似文献
14.
Harutyun Melikyan Arsen Babajanyan Jongchel Kim Barry Friedman 《Journal of magnetism and magnetic materials》2009,321(16):2483-2487
A near-field scanning microwave microscope (NSMM) incorporating an atomic force microscope (AFM) probe tip was used for the direct imaging of magnetic domains of a hard disk under an external magnetic field. We directly imaged the magnetic domain changes by measuring the change of reflection coefficient S11 of the NSMM at an operating frequency near 4.4 GHz. Comparison was made to the magnetic force microscope (MFM) image. Using the AFM probe tip coupled to the tuning fork distance control system enabled nano-spatial resolution. The NSMM incorporating an AFM tip offers a reliable means for quantitative measurement of magnetic domains with nano-scale resolution and high sensitivity. 相似文献
15.
Magnetic hollow spheres of low density were prepared by plating Fe3O4 magnetic films on hollow glass spheres using ferrite plating. The complex permeability and permittivity of spheres–wax composites were measured in the range of 2–18 GHz. The complex permeability and permittivity increased, and the dielectric and magnetic losses were improved as the volume fraction of the magnetic spheres in the composites increased from 60% to 80%, which also resulted in a great improvement of microwave absorption properties. For composites with volume fraction 80%, its magnetic resonance frequency was at about 13 GHz and it appeared three loss peaks in the calculated reflection loss curves; the bandwidth less than −10 dB was almost 4 GHz which was just in the Ku-band frequencies (12–18 GHz) and a minimum reflection loss of −20 dB was obtained when the thickness was 2.6 mm; the microwave absorbing properties were mainly due to the magnetic loss. The results showed that the magnetic spheres composites were good and light microwave absorbers in the Ku-band frequencies. 相似文献
16.
Collection mode near-field microscopy is demonstrated using a 10.56 GHz (X-band) frequency illumination. Imaging of a standing evanescent microwave was experimentally used to evaluate the capabilities of the microscope. The microscope functionality was validated by imaging near field interactions of different systems of dipole-like resonances. We prove that those microscope images contain near-field information by presenting numerical modeling of dipole-like resonant interactions. The model makes use of an analytic Dyadic Green's which is based in the near-field electrostatic approximation. We propose that this microscopy technique can be used, with certain limitations, as a check for 2D mapping of designed (spoof) surface plasmon at microwave frequencies. 相似文献
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G. Pica A. Andreone F. Palomba M. Salluzzo R. Vaglio G. Malandrino V. Ancarani I.L. Fragalà A. Cassinese G. Müller 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,18(3):405-411
We report on the synthesis, structural and electrical characterization of high quality Tl2Ba2Ca1Cu2O8 (Tl-2212) superconducting films. The samples have been grown ex-situ on mm2 LaAlO3 (100) substrates by a combined approach of metal-organic chemical vapor deposition (MOCVD) and thallium vapor diffusion.
The morphological and compositional nature of the c-axis oriented films has been investigated by SEM and X-ray analyses. Typical values of K and MA/cm2 at 77 K have been measured. Microwave measurements have been performed at f
= 87 GHz inserting the film in a copper cavity and at f
=1.5 GHz on patterned samples using a microstrip resonator technique. A penetration depth nm is evaluated by fitting the microwave data with phenomenological equations. The minimum value of the surface resistance
measured at 4.2 K is 60 and 6 m at 1.5 GHz and 87 GHz respectively. The microwave data are described in the context of a modified two fluid model. An evaluation
of the temperature dependence of the scattering rate has been performed through the simultaneous measurement of the surface
resistance and the penetration depth.
Received 16 December 1999 and Received in final form 17 March 2000 相似文献