排序方式: 共有21条查询结果,搜索用时 15 毫秒
1.
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
2.
Organic quantum well and superlattice characteristics in quasi-one-dimensional multiblock copolymers
A tight-binding calculation was presented to describe multiblock copolymers, such as [...-(PA)x-(PPP)y-...] composed of PA (polyacetylene) and PPP (poly(p-phenylene). It is found that a copolymer has a quantum well and superlattice characteristics, and evident is the effect of the composite lengths, the interfacial couplings and the electron-phonon interactions on the electronic properties of a copolymer. The quantum tunneling, the Franz-Keldysh effect and the quantum confinement can be generated under an applied electric field. These results were compared to those of traditional inorganic quantum well and superlattice systems. 相似文献
3.
4.
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
5.
6.
Copolymers which are synthesized by oligomers or homopolymers have quasi-one-dimensional structures. A tight-binding model
was suggested to study the organic quantum-well properties of triblock copolymers xPA/nPPP/yPA and xPPP/nPA/yPPP consisting
of polyacetylene (PA) and poly( p-phenylene) (PPP). It was found that the electronic density in the lowest conductive state
(LUMO) could be tuned by the ratios of homopolymers and interfacial coupling. The spontaneous quantum tunneling effects will
occur in triblock copolymer xPA/nPPP/yPA with the increasing interfacial coupling. 相似文献
7.
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
8.
我们根据一种结构分块模型,计算了与超导转变温度Tc密切相关的块之间相互作用能,讨论了HgBa2CuO4 δ中载流子分布对相互作用能的影响.通过计算不同氧缺陷下,空穴在不同平面以及空穴在Cu-O平面不同位置上对相互作用能的影响,研究了它们与超导电性的关联.计算表明,空穴在Cu-O面上的位置不仅明显地影响到相互作用能的大小,而且影响相互作用能随氧含量的变化趋势,该结果为我们了解载流子在Cu-O面上分布是否均匀提供了一定的线索.结果还表明,HgBa2CuO4 δ中的载流子主要分布在Cu-O平面上. 相似文献
9.
10.
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