共查询到16条相似文献,搜索用时 171 毫秒
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研究了用磁控溅射方法制备的纳米结构Sm22Co78单层膜、Sm22Co78/Fe65Co35双层膜及Sm22Co78/Fe65Co35/Sm22Co78三层膜的磁性,特别是双层膜及三层膜系统中的Fe65Co35软磁层厚度d对薄膜剩磁比(Mr/Ms)和矫顽力(Hc)的影响.所有样品的磁滞回线测量表明,该系列薄膜的易磁化轴在膜面内.磁滞回线的单一硬磁相特征,说明SmCo硬磁层与FeCo软磁层之间的交换相互作用使两相很好地复合在一起.在双层膜和三层膜中,Mr/Ms随软磁层厚度d的增加单调上升,而矫顽力随d的变化出现一峰值.通过研究ΔM随磁场H的变化,发现随着软、硬磁相界面数的增加,ΔM曲线的正峰数量逐渐减少;负峰数量逐渐增强,负峰的半高宽逐渐减少.
关键词: 相似文献
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应用同步辐射X射线衍射(XRD)和广延X射线吸收精细结构边方法(EXAFS),结合反蒙特卡罗(RMC)拟合、Voronoi分形技术等对Zr50Cu50二元和Zr48Cu45Al7三元金属玻璃材料的微观结构进行了系统的研究.结果表明:ZrCuAl三元金属玻璃中Al原子与Zr原子、Cu原子之间存在强相互作用,表现为键长的明显缩短,导致其微观结构中的Voronoi团簇体积普遍小于Zr50关键词:
大块金属玻璃
原子结构
玻璃形成能力
同步辐射技术 相似文献
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过渡金属元素Hf被设计成通过占据Co原子、Zr原子和间隙位点来添加到ZrCoH3中.通过第一性原理计算研究了Hf对ZrCoH3放氢的影响.发现用Hf掺杂会使ZrCoH3不稳定,导致氢离解能(Ed)、Co-H平均单位键长的键序(SBOCo-H)降低,顺序为Zr16Co16H48> Zr16Co16HfH48> Zr16Co15HfH48> Zr15Co16HfH48.理论研究表明在ZrCoH3-Hf体系中,较弱的Co-H共价键相互作用、金属特性和Hf-H键的形成都有利于提高ZrCoH3的放氢能力. Hf原子优先占据间隙位,但这对氢离解能影响很小,氢离解能与位置... 相似文献
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The substitution of iron for cobalt in crystalline Co3B and Co78B22 and Co72Si2B26 glasses has been studied by Mössbauer spectroscopy. In both crystalline and amorphous states, iron preferentially replaces those cobalt atoms which have two boron nearest neighbours. 相似文献
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Superconductivity in ternary metallic glasses has been investigated using the model pseudopotential approach, which has been
found quite successful in explaining superconductivity in metals, binary alloys and binary glasses. It is observed that this
simple methodology successfully explains superconducting behaviour of ternary glasses without requiring the solution of Dirac
equation for a many body problem or estimation of various interactions as required in ab-initio pseudopotential theory. In
the present work superconducting state parameters of fourteen metallic glasses of (Ni-Zr)-M system (M=Ti, V, Co, Cu) have
been determined in the BCS-Eliashberg-McMillan framework. It is observed that addition of V, Co, and Cu as the third element
(M) to a binary metallic glass (Ni33 Zr67) causes the parameters λ,T
c, α, andN
0
V to decrease, and Coulomb pseudopotential (μ*) to increase with concentration of M, showing that the presence of third element (M) causes suppression of superconducting
behaviour of the alloy. The decrease inT
c with increasing concentration of third element (M) may be attributed to the modifications in density of states at the Fermi
levelN(E
F), and probable changes in the band structure of the alloy due to addition of the third element (M). Slight difference is
noticed when Ti is added to the Ni33 Zr67 alloy. In this caseT
c rises initially and then decreases with concentration of M, showing a peak at aboutx=0.05. This indicates that on addition of Ti, 3d states grow near the Fermi level and hence contribute substantially toN(E
F), favouring superconducting behaviour in this case. The present results forT
c show an excellent agreement with the experimental data. QuadraticT
c equations have been proposed, which provide successfully theT
c values of ternary metallic glasses under consideration.
Paper presented at National Conference on Current Trends in Condensed Matter Research, Warangal, India, September 20–22, 2004. 相似文献
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The low temperature specific heat and thermal conductivity of (Cu50Zr50)94Al6 bulk metallic glass have been studied experimentally. A low temperature anomaly in the specific heat is observed in this alloy. It is also found that in addition to Debye oscillators, the localized vibration modes whose vibration density of state has a Gaussian distribution should be considered to explain the low temperature phonon specific heat anomaly. The phonon thermal conductivity dependence on temperature for the sample does not show apparent plateau characteristics as other glass materials do; however, the influence of the resonant scattering from the localized modes on the lattice thermal conductivity is prominent in the bulk metallic glass at low temperatures. 相似文献
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Surface composition and depth profile of native oxide on Fe67Co18B14Si1 metallic glass has been investigated using Auger electron spectroscopy. The native oxide is compared with chemisorbed oxygen on the cleaned surface. Results indicate that boron segregates on the surface in the presence of oxygen. The low energy L23M45M45 peak of iron in metallic glass is compared with that in crystallized sample and pure iron foil. 相似文献
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Zhihao ZhangBeiyu Li Weilong CuiJianxin Xie 《Journal of magnetism and magnetic materials》2011,323(12):1712-1716
Influences of the size factors (glass coating thickness and metallic core diameter) of microwires on GMI effects of the glass-coated Co68Fe4.5Si13.5B14 amorphous microwires were investigated. The results indicated that the GMI effect of the microwires with the same glass coating thickness or the same metallic core diameter was initially increased to a peak and then decreased with an increase in the diameter or the thickness. The glass coating thickness and the metallic core diameter corresponding to the maximum GMI varied with metallic core diameter and glass thickness, respectively. The GMI effect of the microwires with the same geometric size varied remarkably under different cooling rates. Such effect was ascribed to the microstructural changes of the metallic core wire under different cooling rates. The influence of the glass coating thickness on the GMI effect of the microwire was attributed to the synthetical actions of crystallization enthalpy (degree of disorder) and the internal stress. 相似文献
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Annealing temperature dependence of the stress-induced magnetic anisotropy in Co73Mo2Si15B10 (λs < 0) and (Co0.89Fe0.11) 72Mo3Si15B10 (λ > 0) metallic glass ribbons has been studied experimentally. The room temperature values of the induced anisotropy constants K depend strongly on the annealing conditions, and reveal a change of sign at annealing temperatures well below Tcryst. It is concluded that transient creep and steady-state creep at the elevated temperature give rise to compressive and tensile stresses, respectively, in the expression for the magnetoelastic coupling energy at room temperature. 相似文献