共查询到18条相似文献,搜索用时 203 毫秒
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通过求解磁性d波超导中的能隙和磁交换能的自洽方程, 研究磁性d波超导/铁磁/磁性d波超导结中的约瑟夫森电流. 计算结果表明: 1)临界电流随中间的铁磁层厚度呈现出两种不同周期的振荡混合, 通过增强铁磁层中的磁交换能q0和铁磁/磁性d波超导界面处的势垒强度z0, 短周期分量可从长周期中分离出来, 反之, 通过降低q0和z0, 长周期分量可从短周期中分离出来; 2)在两边磁性d波超导的磁化方向取平行时, 在取一些特定的铁磁层厚度下, 磁性d波超导中的磁交换能可增强系统的临界电流.
关键词:
磁性d波超导体
铁磁体
约瑟夫森电流 相似文献
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文章中,通过磁控溅射制备了界面处插入4d,5d元素薄层(包括Ru,Pd,Ag和Au)的Ta/NiFe/Ta多层膜,并对它们的磁输运和磁性以及微结构进行了测试和表征.结果显示,Pd和Pt一样界面效应显著,能有效地提高NiFe薄膜退火前后的AMR比值,并抑制磁性死层.表面能比较小、熔点相对低的插层材料Ag,Au在退火过程中容易通过晶界扩散,强烈破坏其AMR性能.对于熔点高、表面能比较大的插层材料如Ru,磁性死层同样得到了抑制,NiFe薄膜的温度稳定性也可以得到提高.结果表明界面插层从界面电子自旋-轨道散射、界面死层和界面原子扩散等方面深刻影响NiFe薄膜的AMR.
关键词:
各向异性磁电阻
界面效应
原子扩散 相似文献
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建立了一种硫钝化GaAs(100)表面的新方法,即CH3CSNH2/NH4OH溶液处理,应用同步辐射光电子能谱(SRPES)和X射线光电子能谱(XPS)表征了该钝化液处理的n-GaAs(100)表面的成键,特性和电子态.结果表明,经过处理的n-GaAs(100)表面,S既与As成键也与Ga成键,形成S与GaAs的新界面,并且Ga和As的氧化物被移走,这标志着CH3CSNH2/NH4关键词: 相似文献
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超级奥氏体不锈钢中因含有更高铬、钼含量,具有极高的耐点蚀、晶间腐蚀性能,这与Mo等合金元素对钝化膜结构的影响密切相关,尤其含硼超奥钢钝化层表面Cr、Mo含量明显增加,但其原子层次的微观作用机制尚不清楚.本文采用第一性原理方法,研究了置换原子(Mo、Mn、Ni、Si),及间隙原子B在fcc-Fe/Cr2O3界面占位倾向,并分析了可稳定存在于界面B对这些元素偏析倾向的影响.结果表明:Mo、Mn、Ni、Si、B均可与fcc-Fe/Cr2O3界面结构体系形成稳定结构;Mo、Ni倾向分布于界面基体侧,Mo有向氧化层扩散的趋势,B处于fcc-Fe/Cr2O3界面基体侧更稳定,Mn、Si易分布于氧化层中;存在于界面B对四种元素在fcc-Fe/Cr2O3界面体系中的占位影响不同,有利于Mn、Mo偏析于界面基体侧,但抑制Mo向界面基体侧的偏析程度,使得Si、Ni更均匀的分布于基体. Mo等合金元素分布于界面时的态密度来看,界面处M... 相似文献
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O. Bethge C. Henkel S. AbermannG. Pozzovivo M. Stoeger-PollachW.S.M. Werner J. SmolinerE. Bertagnolli 《Applied Surface Science》2012,258(8):3444-3449
La2O3 grown by atomic layer deposition (ALD) and thermally grown GeO2 are used to establish effective electrical surface passivations on n-type (1 0 0)-Ge substrates for high-k ZrO2 dielectrics, grown by ALD at 250 °C substrate temperature. The electrical characterization of MOS capacitors indicates an impact of the Ge-surface passivation on the interfacial trap density and the frequency dependent capacitance in the inversion regime. Lower interface trap densities can be obtained for GeO2 based passivation even though a chemical decomposition of the oxidation states occur during the ALD of ZrO2. As a consequence the formation of a ZrGeOx compound inside the ZrO2 matrix and a decline of the interfacial GeO2 are observed. The La2O3 passivation provides a stable amorphous lanthanum germanate phase at the Ge interface but also traces of Zr germanate are indicated by X-ray-Photoelectron-Spectroscopy and Transmission-Electron-Microscopy. 相似文献
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Kwan Hong Min Sungjin Choi Myeong Sang Jeong Min Gu Kang Sungeun Park Hee-eun Song Jeong In Lee Donghwan Kim 《Current Applied Physics》2019,19(2):155-161
Plasma-assisted atomic layer deposition (PA-ALD) is more suitable than thermal atomic layer deposition (ALD) for mass production because of its faster growth rate. However, controlling surface damage caused by plasma during the PA-ALD process is a key issue. In this study, the passivation characteristics of Al2O3 layers deposited by PA-ALD were investigated with various O2 plasma exposure times. The growth per cycle (GPC) during Al2O3 deposition was saturated at approximately 1.4?Å/cycle after an O2 plasma exposure time of 1.5?s, and a refractive index of Al2O3 in the range of 1.65–1.67 was obtained. As the O2 plasma exposure time increased in the Al2O3 deposition process, the passivation properties tended to deteriorate, and as the radio frequency (RF) power increased, the passivation uniformity and the thermal stability of the Al2O3 layer deteriorated. To study the Al2O3/Si interface characteristics, the capacitance-voltage (C-V) and the conductance-voltage (G-V) were measured using a mercury probe, and the fixed charge density (Qf) and the interface trap density (Dit) were then extracted. The Qf of the Al2O3 layer deposited on a Si wafer by PA-ALD was almost unaffected, but the Dit increased with O2 plasma exposure time. In conclusion, as the O2 plasma exposure time increased during Al2O3 layer deposition by PA-ALD, the Al2O3/Si interface characteristics deteriorated because of plasma surface damage. 相似文献
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Interface engineering with an MOCVD grown ZnO interface passivation layer for ZrO2-GaAs metal-oxide-semiconductor devices 总被引:1,自引:0,他引:1
This work deals with the fabrication of a GaAs metal-oxide-semiconductor device with an unpinned interface environment. An ultrathin (∼2 nm) interface passivation layer (IPL) of ZnO on GaAs was grown by metal organic chemical vapor deposition to control the interface trap densities and to prevent the Fermi level pinning before high-k deposition. X-ray photoelectron spectroscopy and high resolution transmission electron microscopy results show that an ultra thin layer of ZnO IPL can effectively suppress the oxides formation and minimize the Fermi level pinning at the interface between the GaAs and ZrO2. By incorporating ZnO IPL, GaAs MOS devices with improved capacitance-voltage and reduced gate leakage current were achieved. The charge trapping behavior of the ZrO2/ZnO gate stack under constant voltage stressing exhibits an improved interface quality and high dielectric reliability. 相似文献
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《Current Applied Physics》2020,20(1):132-136
Recently, spintronics devices using MoS2 and ferromagnetic electrode have been in the spotlight. However, strong Fermi level pinning (FLP) is known to occur between MoS2 and ferromagnetic electrode, resulting in a large Schottky barrier height (SBH), which makes it difficult to inject electron from ferromagnetic electrode to semiconductor. To resolve this problem, we study the reduction of FLP occurring between two materials by investigating the effect of atomic passivation at Ni-MoS2 interfaces on contact behaviors. Such atomic passivation can reduce the FLP and magnetic moments induced at S atoms of MoS2. Especially, the largest decrease in the FLP occurs in the case of H atom passivation. Besides, the N, O, and F atom passivation confirms the possibility of ohmic contact, indicated from small SBHs (~0.2 eV). As a result, the SBH and thus the efficiency of the device can be controlled by atomic passivation at metal-semiconductor interfaces. 相似文献
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利用磁控溅射和快速热处理的方法制备了Mn,B共掺的多晶硅薄膜(Si0.9654Mn0.0346:B).磁性和结构研究发现薄膜有两个铁磁相.低温铁磁相来源于杂相Mn4Si7,高温铁磁相(居里温度TC~250K)是由Mn原子掺杂进入Si晶格导致.晶化后的薄膜利用射频等离子体增强化学气相沉积系统(PECVD)进行短暂(4min)的氢化处理后发现,薄膜的微结构没有发生变化而饱和磁化强度却随着
关键词:
磁性半导体
硅
氢化 相似文献
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The influence of DC current on the resistivity and phase transition of polycrystalline La0.7Ca0.3MnO3 has been investigated. The specific heat measurement found that charge carriers and ferromagnetic spin-wave contributions were changed after applied DC current. Applying high electric fields leads to the formation of ferromagnetic regions. The resistivity drops abruptly once the percolating current path is established. As current through the sample disappears, the larger ferromagnetic (FM) clusters, however, remain and are frozen in giving a measurable contribution to the specific heat of the system. The larger clusters should give rise to the value of spin-wave stiffness constant (D), as it is expected to increase the strength of the ferromagnetic coupling. The metallic ferromagnetic regions would make the charge carrier delocalization and attribute to specific heat linear term γ. 相似文献
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The transport properties and magnetic phase transitions of charge ordering manganites Nd0.5Sr0.5MnO3 have been investigated. From resistivity measurements, a continuous increase of resistivity upon the thermal cycling occurs at , and shows an instable behavior in the system. The experimental results of magnetization and electron-spin-resonance spectra indicate that the ferromagnetic phase and antiferromagnetic phase coexist in a broad temperature region. We think that the origin of the instability stems from an inhomogeneous strain yielded in the ferromagnetic interface, due to the competition among different phases. 相似文献