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HDDR过程中三元和多元Nd-Fe-B合金磁畴结构的MFM研究 总被引:1,自引:1,他引:1
用磁力显微镜研究了三元Nd-Fe-B合金在HDDR过程的不同阶段(铸态、不充分吸氢歧化、充分吸氢歧化和脱氢再复合)的破畴结构。在铸态样品表面清楚地观察到了易磁化轴互相垂直的柱状晶表面的两类磁畴图型。当样品不充分吸氢歧化和充分吸氢歧化时,破畴结构明显发生变化,反映了Nd-Fe-B的分解产物NdH2,α-Fe和Fe2B及其微晶结构的变化。脱氢再复合后形成的微晶的磁畴结构则表明样品保留了铸态样品柱状晶的构型。此外,还对比研究了多元Nd-Fe-B合金在HDDR过程中的磁畴结构,并根据微磁结构分析,指出过量的Ga元素添加可抑制Nd2(Fe,M)14B相的吸氢歧化,从而导致相应HDDR粘结磁体性能降低。 相似文献
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Magnetic Microstructures of PryFe90-yB10 (y = 8-11.76) Nanocrystalline Ribbons Using Magnetic Force Microscopy * 下载免费PDF全文
Magnetic microstructure of melt-spun PryFe90-yB10 (y = 8, 8.5, 9, 9.5, 10 and 11.76) nanocrystalline ribbons in an as-grown state has been studied using a magnetic force microscope. The magnetic domains are characterized by dark areas adjacent to bright areas in a sub-micron scale and in random distribution. By comparing with the size of the micro-crystals measured from the TEM image, the exchange coupling effect was confirmed to exist inall the ribbons. Using the roughness analysis, the variation of the root mean-square values of the phase shifts obtained from the magnetic force images versus the content y of Pr were measured, which is very consistent with the curve of the residual induction Bγ versus the content y. 相似文献
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The domain structures of Nd13Fe80B7 alloy at different stages of the HDDR process have been revealed using a magnetic force microscope. In the as-cast samples, the columnar crystals with easy axis perpendicular to one another are clearly characterized by their different domain structures. For the insufficient and sufficient HD treatment, an obvious change of domain structure occurs, which is related to the variation of composition and crystalline microstructure during the HD process. And for the samples after sufficient DR processing, it is confirmed that the configuration of the columnar crystals is retained by the detected domain structures. 相似文献
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Effect of RF power on the properties of transparent conducting zirconium-doped zinc oxide films prepared by RF magnetron sputtering 总被引:2,自引:0,他引:2 下载免费PDF全文
Transparent and conducting zirconium-doped zinc oxide films with
high transparency and relatively low resistivity have been
successfully prepared by radio frequency (RF) magnetron sputtering
at room temperature. The RF power is varied from 75 to 150W. At
first the crystallinity and conductivity of the film are improved
and then both of them show deterioration with the increase of the RF
power. The lowest resistivity achieved is 2.07×10-3\Omegacm
at an RF power of 100W with a Hall mobility of
16cm2V-1s-1 and a carrier concentration of
1.95×1020cm-3. The films obtained are polycrystalline
with a hexagonal structure and a preferred orientation along the
c-axis. All the films have a high transmittance of approximately
92% in the visible range. The optical band gap is about 3.33eV
for the films deposited at different RF powers. 相似文献
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Magnetic and Crystalline Microstructures of the Sr-La-Co M-type Ferrites by Magnetic Force Microscopy 下载免费PDF全文
With proper erosion of sample surface and making a grid of crystal boundaries, the magnetic and crystal1ine microstruct ures of Sr-La-Co M-type ferrites of nominal composition of La0.2 Sr08Fe11.8Co0.2 O19 (at. %) have been investigated by using magnetic force microscopy. By calculating average diameter and thickness, and average alignment degree of the grains of the ferrites, recognizing their domain patterns and calculating the proportion of grains with single domain or multi-domains, the Sr-La-Co M-type ferrites with high magnetic performance have been characterized at microcrystalline and micromagnetic level. In addition, we has interpreted why the grains always present plate-like domains. 相似文献
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Intrinsic relationship between photoluminescence and electrical characteristics in modulation Fe-doped AlGaN/GaN HEMTs 下载免费PDF全文
The photoluminescence(PL) and electrical properties of Al GaN/GaN high electron mobility transistors(HEMTs) with different Fe doping concentrations in the GaN buffer layers were studied. It was found that, at low Fe doping concentrations,the introduction of Fe atoms can result in a downward shift of the Fermi level in the GaN buffer layer, since the Fe atoms substitute Ga and introduce an Fe_(Ga)~(3+/2+) acceptor level. This results in a decrease in the yellow luminescence(YL) emission intensity accompanied by the appearance of an infrared(IR) emission, and a decrease in the off-state buffer leakage current(BLC). However, a further increase in the Fe doping concentration will conversely result in the upward shift of the Fermi level due to the incorporation of O donors under the large flow rate of the Fe source. This results in an increased YL emission intensity accompanied by a decrease in the IR emission intensity, and an increase in the BLC. The intrinsic relationship between the PL and BLC characteristics is expected to provide a simple and effective method to understand the variation of the electrical characteristic in the modulation Fe-doped HEMTs by optical measurements. 相似文献
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与传统稳定同位素技术相比,甲烷团簇同位素技术具有分辨率高、检出限低的优点,从而为甲烷产生机制和转化过程研究提供了新的视角。甲烷的两种团簇同位素体13CH3D和12CH2D2具有独特的物理与化学性质,并可提供甲烷内部同位素平衡状态的重要信息。目前国内刚建立了对这两种团簇同位素体的测试方法,部分指标的测试精度有待于进一步提高。该文依托国内首台高分辨气体稳定同位素质谱仪(HR-IRMS),通过平衡仪器的分辨率和灵敏度,对甲烷团簇同位素12CH2D2测试方法进行优化,在关闭Aperture选项条件下通过峰拖尾校正,可使[12CH2D2+]信号得到有效提高,并通过[H2O+]峰模拟计算校正13CH3D峰与13CH5峰拖尾产生的空白。基于连续测试,成功地将测试精度提高到1.29‰,达到国际水平。 相似文献
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