Structural and Magnetic Properties of Amorphous and Nanocrystalline CoFeSiB Thin Films

This study examined the structural, magnetic, and transport properties of CoFeSiB films with various Co compositions. The main focus was on two samples, amorphous $hbox{Co}_{74}hbox{Fe}_{4}hbox{Si}_{14}hbox{B}_{8}$ and nanocrystalline $hbox{Co}_{78}hbox{Fe}_{2}hbox{Si}_{12}hbox{B}_{8}$ thin films. The results show that the amorphous film is a typical soft magnetic material, while the nanocrystalline film has a large saturation field. It is believed that in a nanocrystalline thin film, a large saturation field is caused by antiferromagnetic exchange at the boundary between the amorphous and nanocrystalline phases.      

软磁性薄膜微波磁特性的研究进展

概述了软磁性单层膜、多层膜、颗粒膜的微波磁特性研究进展,对这些薄膜的基本磁性和微波磁性进行了总结和讨论,得出软磁纳米晶薄膜可望成为应用于微波领域的主体候选材料,指出了Co(Fe)基软磁性薄膜微波特性的研究方向.     

Microstructure and Magnetic Properties of Electrodeposited Fe-Based Thin Films on Silicon Substrate Under Heat Treatment

Three kinds of Fe-based thin films, Fe–20%Ni–80%, Fe–60%Co–40%, and Fe–10%Ni–60%Co–30% (at %), were prepared on silicon (1 1 1) substrates by direct current electrodeposition with the optimized plating conditions. Films were annealed at various temperatures from 200 to 400 °C, varying time from 2 to 4 h. The microstructure, surface morphology, and chemical composition have been investigated by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometer with electron probe micro-analysis, respectively. The magnetic properties were measured by the superconducting quantum interference device magnetometer. Effect of heat treatment on films is then discussed.     

Structural,Morphological, and Magnetic Properties of Electrodeposited CoNi Thin Films on the FTO Substrate

Journal of Superconductivity and Novel Magnetism - CoNi films were elaborated by electrodeposition onto FTO substrates using a chloride bath with a metallic ion molar ratio [Co2+]/[Ni2+] equals...     

纳米晶软磁材料的发展、磁特性及展望

本文首先回顾了纳米晶软磁材料的发展过程。对其合金化、磁性能特别是制备工艺作了较详细的介绍，分析了优异软磁性能的起因，最后对纳米晶软磁材料的发展趋势作了展望。     

几种新型铁基纳米晶软磁合金的磁性能

用较便宜的元素Mo、W、V和Cr部分或全部代替较昂贵的Nb,我们发展了一些新的铁基纳米晶软磁合金,它们仍象Fe-Cu-Nb-Si-B纳米晶合金那样具有优良的综合软磁性能。本文扼要地报道新开发的5种铁基纳米晶合金的直流和交流磁性能,并与已报道的Fe-Cu-Nb-Si-B合金和功率Mn-Zn铁氧体H_(74)的性能做了比较。特别是新发展的Fe-Cu-Cr-V-Si-B合金的高频铁损已达到P_(2/100k)=171kW/m~3,P_(2/100k)=395kW/m~3和P_(2/200k)=579kW/m~3的水平,这明显优于Fe-Cu-Nb-Si-B的水平。     

Structural and Magnetic Properties of Co diffused CdTe Nanocrystalline Thin Films Deposited by Electron Beam Evaporation

Co diffused cadmium telluride (CdTe) nanocrystalline thin films with different Co content were prepared by depositing CdTe/Co stacked layers on glass substrates at 373 K using electron beam evaporation technique. The effect of Co content on structural, morphological, chemical, Raman, and magnetic studies were carried out. X-ray diffraction (XRD) patterns confirmed that all Co diffused CdTe films are in zinc blende structure. The lattice parameter increased with increase of Co content. The high-resolution scanning electron microscopy (HRSEM) images illustrated the grain size of the films. EDAX data confirmed the presence of Co, Cd, and Te with nearly stoichiometic. Raman spectra revealed peaks corresponding to A1, TO, and LO modes of CdTe and gradual shift in peak position. The increase in intensity confirmed the incorporation of Co into CdTe host lattice. Magnetic measurements showed a clear well-defined room temperature ferromagnetic hysteresis loop.     

Tensile Properties of Electrodeposited Nanocrystalline FCC Metals

Bulk nanocrystalline Ni and Ni-15wt%Fe alloy were fabricated via electrodeposition techniques. The nominal grain size of nickel samples was varied from 15 to 200 nm by employing different deposition parameters. The grain size was further reduced to 9 nm by alloying nickel with iron. The tensile properties were evaluated at room temperature using dog-bone shaped samples. The results of this study confirm that strength and strain hardening rate increase with decreasing grain size. The fracture behavior was found to depend on the grain size, presence of large and small defects, and the stress state. The tensile elongation and reduction in area varied significantly among the samples and did not correlate with the fracture behavior. Three categories of behavior were identified. In Type I the samples showed completely ductile fracture but very low tensile elongation. In Type II the samples showed a relatively brittle behavior but impressive tensile elongation. In Type III the samples showed ductile behavior with reasonable tensile elongation. In this article, the tensile elongation and the fracture mode of nanocrystalline face centered cubic (FCC) metals are discussed in terms of deformation behavior and presence of defects.     

NiFeNb薄膜的磁特性及磁阻效应研究

研究了射频磁控溅射膜（Ｎｉ８１Ｆｅ１９）１００－Ｎｂｘ的各向异性磁阻效应ＡＭＲ、矫顽力Ｈｃ、饱和磁化强度４ｘｍｓ和饱和磁化场Ｈ。研究其作为磁阻磁头材料和低磁场高灵敏度材料的可能性。我们发现Ｎｂ的含量对（Ｎｉ８１Ｆｅ１９）１００－ｘＮｂｘ的各向异性磁阻效应ＡＭＲ＝２％、矫顽力Ｈｃ＝１１９Ａ／ｍ和饱和磁化场Ｈｘ＝４４５Ａ／ｍ，适宜于低磁场高灵敏度检测材料。     

Deformation Strength of Nanocrystalline Thin Films

The data of deformation strength and microstructure of thin films of nanocrystalline Pd recently provided by Colla et al. have been analysed. It is shown that the properties of the films with cylindrical grains of30 nm diameter extending over a significant portion of the film thickness(≈90 nm) are quantitatively comparable to what is known from nanocrystalline bulk material. This is explained in terms of boundarymediated processes governing emission, storage, and recovery of dislocations.     

Electric Field Assisted Improving the Quality and Magnetic Properties of Electrodeposited FeCo Films

Journal of Superconductivity and Novel Magnetism - We reported an electric field-assisted deposition process for the improvement of the quality of FeCo film. The films were fabricated by...     

较薄坡莫合金薄膜的磁性能和结构

基于辉光放电原理在不同的溅射气压下制备的NiFe薄膜,发现较低溅射气压下比较高溅射气压下制备的NiFe薄膜的磁性能要好得多.较低溅射气压下制备的NiFe(12nm)薄膜,各向异性磁电阻(AMR)值达到1.2%,而其矫顽力却只有127.4A/m.结构分析表明较低溅射气压下制备的NiFe薄膜结构缺陷较少,内应力小;而较高溅射气压下制备的NiFe薄膜结构缺陷较多,内应力大.     

Surface Morphology, Structural and Magnetic Properties of Electrodeposited NiFeCu/Cu Films

The magnetic and structural properties of the NiFeCu/Cu films electrodeposited on polycrystalline titanium (Ti) substrates and their characterizations were studied. The structural analysis by X-ray diffraction (XRD) has revealed that all films have face-centred cubic (FCC) structure. On the other hand, the XRD analysis showed that the degree of (111) texture is dependent on the Cu content within the film. The composition analysis was carried out by energy-dispersive X-ray spectroscopy (EDX). The result of EDX indicated that the Cu content within the film increases with increasing of non-magnetic Cu layer thickness. The hysteresis loops of the films measured by vibrating sample magnetometer (VSM) showed that all films have a small coercivity typical for soft magnetic materials. The surface morphological structure of the films was investigated by atomic force microscopy (AFM). AFM images indicated that all films have main grains (globular islands) and smaller secondary grains on the main grains with different sizes. The differences observed in the magnetic properties of the films were attributed to the Cu content within the films.     

Optical Properties of Spin-Deposited Nanocrystalline Ni-Zn Ferrite Thin Films Processed by Sol-Gel

Nano crystalline Zn-substituted Ni ferrite films with compositions of Ni_1?xZn_xFe₂O₄ (x = 0.25, 0.50, 0.75) were synthesized by sol–gel spin coating method. The synthesized films were characterized for their structural, morphology, optical, electric, and magnetic properties using x-ray diffraction, scanning electron microscope, UV-Vis spectrometer, two probe resistivity, and vibrating sample magnetometer techniques, respectively. The corresponding results indicate that zinc content has significant effect on physical, magnetic, and optical properties of the ferrite. X-ray diffraction studies of thin films showed that the samples have pure cubic spinel phase. The crystallite size is of the nanoparticles estimated using Debey-Scherrer’s method was found to be in the range of 10.27 to 14.97 nm. The lattice parameter was found to be increased from 8.35 to 8.40 Å with increasing Zn²⁺ contents. The morphology of the thin films depicted the formation of well-developed nano-sized clusters with homogeneous and agglomerated. The optical absorption seen to be affected due to the presence of Zn in Ni-Zn ferrite thin films. Ni-Zn ferrite thin films possess small coercivity and remnant magnetization, which indicates the soft magnetic nature of the material. Electrical resistivity of the films decreases with increasing temperature, suggesting the semiconducting nature of the samples.     

溅射FeSiAl合金薄膜的结构及软磁性能

Ｓｅｎｄｕｓｔ合金是制做薄膜磁头和ＭＩＧ磁头的理想材料，本工作用射频溅射法了备了Ｓｅｎｄｕｓｔ成分的ＦｅＳｉＡｌｗ合金薄膜，研究了制备对膜结构和软磁性能的影响，并对其机理进行了讨论。     

纳米晶PLT薄膜的合成与表征

纳木材料的制备技术结合Ｓｏｌ－Ｇｅｌ工艺在（１００）单晶硅上制备了粒径在２０～８０ｎｍ的多晶ＰＬＴ（Ｐｂ＿（１－ｘ）Ｌａ＿ｘＴｉＯ＿３）纳采晶膜，并用ＩＲ、ＴＧＡ、ＸＲＤ、ＳＥＭ等对膜的制备过程及结果进行了研究。结果表明，所制各的ＰＬＴ纳米晶膜属多晶钙钦矿结构，薄膜表面平整致密，厚度均匀，约为１μ，颗粒为球形或椭球形，粒度呈对称分布。     

电沉积Ni-Cr合金电化学行为的研究

利用线性电位扫描法对在不同Ni2 浓度、Cr3 浓度、温度和pH值下电沉积Ni-Cr合金的电化学行为进行了研究.结果表明,随着镀液中Cr3 和Ni2 浓度的增大,Ni-Cr合金的析出电势向正向偏移,说明增大混合液中的主盐浓度有利于合金的共沉积;随着镀液温度升高和pH值的降低,电沉积Ni-Cr合金阴极极化程度减小,合金析出电势正向偏移;通过计算Ni-Cr合金共沉积电极反应的表观活化能,得到电极电势在-0.85～-1.05 V时,表观活化能均大于40 kJ/mol,说明Ni-Cr合金共沉积是受电化学控制.     

不同晶态比条件下氢化纳米硅薄膜的力学性能

采用射频（radio frequency,RF,13.56MHz）和直流偏压双重激励源,在等离子增强化学气相沉积（plasma-cnhanced chemical vapor deposition,PECVD）系统下制备了康宁玻璃7059衬底上的氢化纳米硅薄膜保持射频功率、反应室气压、直流偏压值和衬底温度等工艺参数不变的情况下,主要改变硅烷稀释度（silanc concentration．sc）从1％到0．5％当SC减小时,薄膜的晶态比Xc反而出现了增大现象,表明较低的SC有利于薄膜结构中晶态成分的形成．当SC减小到0．5％时,气则出现最大值54．2％.文中具有不同薄膜晶态比的样品力学性能采用美Hysitron公司的Tribolndenter纳米压痕系统进行测量,薄膜的杨氏模量和硬度值利用Oliver和Pharr的解析方法得出．结果表明：当薄膜的Xc从50．5％增大到54.2％时,薄膜的杨氏摸量和硬度值都大大增加,这种现象的产生是由于不同Xc的薄膜具有不同的晶态微结构,因此薄膜的Xc值在很大程度上决定薄膜的力学性能.