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硅粉在高氮压下氮化的研究 总被引:4,自引:1,他引:3
本文对三种不同纯度的硅粉在加压氮气(~1MPa)中进行氮化研究。实验表明:在1250~1370℃1h 内硅粉可快速氮化反应生成氮化硅,主要晶相为β-Si_3N_4。硅粉快速氮化时,存在一个临界氮气压力,临界压力大小与硅粉本身表面特性有关,采用适当的工艺参数可快速制备高质量的α-SiN_4粉末。 相似文献
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高密度磁记录材料——纳米磁性团簇研究进展 总被引:1,自引:0,他引:1
报导有关纳米磁性团簇的一些最新研究成果。根据团簇组成成分的不同,将其分为铁磁金属团簇铁磁合金团族、铁磁化合物团簇及嵌埋式铁磁团簇四大类,分别就其制备方法、磁性能及应用前景等进行了综述。对各类团簇的优缺点进行了评述。 相似文献
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概述了新型超硬材料-氮化碳的晶体结构和合成C3N4的实验方法,以及C3N4薄膜的TED,XRD,XPS,FTIR,Raman和Hv的测试结果。 相似文献
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After describing briefly the principles of magnetic recording and the manufacture of media, the author reviews the history, characteristics, and development trends of the most important particulate magnetic recording materials. These are acicular iron oxides, chromium dioxide, cobalt-modified iron oxides, acicular metal particles, and barium ferrite. A trend common to most of the materials is particle size reduction 相似文献
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Previous reports have detailed the fabrication of media able to support high density magnetic recording in both longitudinal and perpendicular formats by the global rapid thermal processing of sputtered non-magnetic precursor films. During processing in this manner a magnetic element is released from its nitride and agglomerates to form a random near mono-dispersion of magnetic nano-particles. Here we explore, primarily through modelling and simulation, the feasibility of processing similarly formulated precursor media not globally but locally. We investigate the potential of using conducting nano-probe tips to produce, via electro-thermal (Joule) heating, a nano-patterned recording medium in the form of regular arrays of magnetic islands in a non-magnetic host. In the first instance we concentrate on the simplest cobalt based precursor medium for which both initial simulation and experimental studies indicate the formation of magnetic islands with dimensions of the order of the tip diameter; this is relatively straightforward. The results signify that if practical production scenarios can be devised to produce technologically significant areas of recording media by the rapid multi-probe repetition of this technique, then processing in this manner offers a promising route to areal recording densities of perhaps 5 Terabit/in(2) even with the simplest cobalt media. We also note that the electro-thermal processing method is potentially extendable to the production of a wide variety of magnetic materials (e.g.?PtCo, FeCo, NiFe alloys) and, applied via electrical nano-imprinting type techniques, to the production of a wide variety of patterned structures. 相似文献
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在NH3/H2气氛下对转炉烟尘进行了还原与氮化的连续处理,以穆斯堡尔谱学结合X光衍射方法对处理试样进行物相分析.实验结果表明,氮化温度为560℃,NH3/H2比小于11时,γ-Fe4N的含量超过70%,处理试样的比饱和磁化强度σs高达140emu/g,较原始样品的有明显增加. 相似文献
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An electrochemical and environmental chamber study of the effects of corrosion on the magnetic properties of various cobalt chromium thin-film compositions is reported. The propensity of these various materials towards corrosion is delineated, with suggestions for an optimum composition with respect to corrosion resistance. The effects of the presence of a titanium seed layer and those of a soft nickel/iron keeper layer on the corrosion resistance of the recording medium are studied 相似文献
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Perpendicular magnetic recording performance for double-layer (Co-Cr,Ni-Fe) media was analyzed, with a simple magnetization model, in comparison with single-layer media. The calculated output voltage from a ring-shaped reproducing head shows good agreement with experimental data. It is shown theoretically and empirically that the Co-Cr layer thickness can be reduced without sacrificing the output amplitude, if the Ni-Fe layer is placed underneath it to perform as a "flux sink" to extinguish the rear surface charge on the Co-Cr layer. 相似文献
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Yamaura M. Yatabe T. Matsuzawa H. Kadokura S. Sobajima S. 《IEEE transactions on magnetics》1986,22(5):349-351
Wear properties of sputtered Co-Cr/permalloy double layer on flexible substrate with and without an inorganic protective top layer were studied under simulated tribological conditions. A soft head slider (ex. glass) gave even severer damage to media than the hard one (ex. Al2 O3 -TiC), and a 200 Å thin inorganic protective top layer was effective enough to enhance resistance against wear. Read-write experiments were also done with use of the double layer flexible media with the protective top layer (200 Å in thickness) by running them on a specially designed driver unit with an Al2 O3 .TiC spherical SPT head. An out-put signal loss was no more than 3dB even after 10 million times of the head passes. 相似文献
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Multi-layer nanocomposite structures of Ta/Ru/CoCr1/FeCoTaCr(soft magnetic layer)/CoCr2/CoCrPt-SiO2(hard magnetic layer or recording layer)/C and Ta/Ru/CoCr1/CoCrPt-SiO2/CoCr2/FeCoTaCr/C were proposed. This exchange coupled composite (ECC) media consisting of hard/soft stacked magnetic layers were promising in improving the writability of perpendicular magnetic recording media. A small CoCrPt c-axis orientation dispersion of about 3° was achieved with the optimized sputter conditions. The CoCrPt-SiO2 grains were well segregated by SiO2 at grain boundaries. The macro-magnetic properties showed that the stacked magnetic grains switched in a coherent mode and that switching field decreased with increasing the thickness of the soft magnetic layer. 相似文献
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Preparation of fibre-like silicon nitride from silicon powder 总被引:1,自引:0,他引:1
P. S. Gopalakrishnan P. S. Lakshminarasimham 《Journal of Materials Science Letters》1993,12(18):1422-1424
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Fabrication processes of arrayed magnetic nanodots for the use of patterned magnetic recording media were reviewed. One candidate for the patterned media is ordered assemble of magnetic nanoparticles, and the other is patterned magnetic thin films fabricated using various micro/nano scale machining processes. For the formation of patterned masks and molds, lithography processes as well as self-organized pattern formation are utilized. For the deposition processes of magnetic dots, electrochemical deposition processes were widely used. These fabrication processes are reviewed mainly from recent reports. The recording systems for the patterned media including probe-type-recording are also overviewed. 相似文献