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L.H. Kong R.R. ChenT.T. Song Y.L. Gao Q.J. Zhai 《Journal of magnetism and magnetic materials》2011,323(24):3285-3289
The magnetic properties and the annealing process of Fe78Zr7B15 amorphous ribbons are investigated by X-ray diffraction (XRD), differential scanning calorimetry, and vibrating sample magnetometer. The fully amorphous structure of the as-quenched ribbons is confirmed by the XRD pattern. The Curie temperature and the saturation magnetization Ms of the ribbons are 305 °C and 124.3 emu/g, respectively. Annealing at 550 °C can result in an increase in Ms with annealing time due to the increasing crystallized volume fraction of α-Fe phase. The optimized annealing process is established at 550 °C for 20-30 min with maximum Ms of 146.6 emu/g. The morphology of the ribbons annealed at 550 °C is observed by scanning electron microscopy, showing that nanocrystalline α-Fe grains are dispersed in an amorphous matrix. 相似文献
65.
The influence of a few percent neodynium additives to Fe-B alloy on the hyperfine parameters was investigated. It was found
that Nd decreases the hyperfine field of amorphous Fe-B alloys. The samples annealed at temperatures between 600°C and 700°C
contain α-Fe and Fe3B phases. The average hyperfine field of Fe3B phase increases with increasing Nd content and decreases with increasing annealing temperature. The average isomer shift
of Fe3B phase decreases with increasing Nd content. The experimental data show that the change of hyperfine parameters of the Fe3B phase in the studied alloys is due to Nd atom. 相似文献
66.
First-principles study of mechanical stability and thermal properties of MNNi3 (M=Zn,Mg,Al) under pressure 下载免费PDF全文
The mechanical stability,elastic,and thermodynamic properties of the anti-perovskite superconductors MNNi 3(M=Zn,Mg,Al) are investigated by means of the first-principles calculations.The calculated structural parameters and elastic properties of MNNi 3 are in good agreement with the experimental and the other theoretical results.From the elastic constants under high pressure,we predict that ZnNNi 3,MgNNi 3,and AlNNi 3 are not stable at the pressures above 61.2 GPa,113.3 GPa,and 122.4 GPa,respectively.By employing the Debye model,the thermodynamic properties,such as the heat capacity and the thermal expansion coefficient,under pressures and at finite temperatures are also obtained successfully. 相似文献
67.
Simultaneous excitation of cavity resonance (CR) and surface plasmon resonance (SPR) was observed in the angular spectrum
by substituting Ag/Al2O3/Ag layers for the metal film in a Kretschmann structure. Two reflective valleys, elicited respectively by CR and SPR, appeared
at different positions in the angular spectrum. The former is the sum of enhanced transmission of CR and absorption of the
metal, expressed in the reflection spectrum and extremely insensitive to the changes of the surface environment (refractive
index). The latter behavior is like that when two metal films are stuck together: it has almost the same resonance depth and
width, and is extremely sensitive to the changes of the surface environment. Moreover, two SPR peaks could be excited simultaneously
at one angle but with different wavelengths in the frequency spectrum, which is not seen in traditional Kretschmann structures. 相似文献
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Although the investigation on photonic band gap materials has been done more than two decades, it is still a big challenge
to fabricate three-dimensional photonic crystal (PC) possessing wide band gaps in visible range. In this article, we have
reviewed recent progresses on fabricating the PC with low refractive index material in visible range. In contrast to the material
with large refractive index, it is cheap to use low refractive index material in fabricating the PC and will be greatly beneficial
for future industrial productions. The holographic method to fabricate such a PC has been introduced, applying it to the design
of the microlaser has also been discussed. 相似文献
70.
ZnO nanoparticles were prepared by a simple chemical synthesis route. Subsequently, SiO2 layers were successfully coated onto the surface of ZnO nanoparticles to modify the photocatalytic activity in acidic or alkaline solutions. The obtained particles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectrometry (EDS) and zeta potential. It was found that ultrafine core/shell structured ZnO/SiO2 nanoparticles were successfully obtained. The photocatalytic performance of ZnO/SiO2 core/shell structured nanoparticles in Rhodamine B aqueous solution at varied pH value were also investigated. Compared with uncoated ZnO nanoparticles, core/shell structured ZnO/SiO2 nanoparticles with thinner SiO2 shell possess improved stability and relatively better photocatalytic activity in acidic or alkaline solutions, which would broaden its potential application in pollutant treatment. 相似文献