共查询到20条相似文献,搜索用时 125 毫秒
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用脉冲激光沉积(PLD)的方法在硅单晶基片上制备了Ti90Cr10和Co80Cr20/Ti90Cr10薄膜,用XRD研究了Ti90Cr10薄膜的晶体结构与制备温度的关系,结果表明随着温度升高,薄膜从非晶态逐步向晶态转化,并且计算了Ti90Cr10薄膜的晶粒大小以及晶格常数.利用透射电镜对Ti90Cr10薄膜进行了表面和截面形貌的表征.采用纳米压痕仪对Ti90Cr10薄膜的硬度和膜基界面结合力进行了分析,表明薄膜的硬度和膜基结合力随制备条件改变有所变化,制备温度增加,薄膜的硬度和膜基结合力随之增加.利用Ti90Cr10薄膜作为中间层,用PLD制备了Co80Cr20磁性层,获得了很好的垂直磁化性质,膜厚减小,矫顽力和矩形比有所增加,600℃真空条件下制备的Co80Cr20(8 nm)/Ti90Cr10(14 nm)薄膜的矫顽力为65.25 kA/m,矩形比为0.86,并且讨论了Co80Cr20/Ti90Cr10薄膜的磁化性质. 相似文献
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利用同步辐射光电发射和铁磁共振(FMR)研究了Co/GaAs(100)界面形成以及Co超薄膜的磁性质.结果表明,在低覆盖度(约为0.2nm)下,Co吸附原子与衬底发生强烈的界面反应,在覆盖度为0.9nm时,形成稳定的界面.从衬底扩散出的Ga原子与Co覆盖层合金化,而部分As原子与Co原子发生反应,形成稳定的键合,这些反应产物都停留在界面处很窄的区域(0.3—0.4nm)内.另一部分As原子偏析在Co覆盖层表面.结合理论模型,详细地讨论了界面结构及Ga,As原子的深度分布.FMR结果表明,生长的Co超薄膜具
关键词: 相似文献
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系统研究了由非晶态Fe-Si合金与Si、Cu,、Pd和Cr四种不同类型的材料组合而成的磁性多层膜的二维磁性,界面的死层效应和极化效应,层间耦合作用,在Fe-Si/Cr多层膜研究中,发现了饱和磁化强度随Cr层厚度的改变而出现振荡变化的现象,这是由于磁性层中内地场的变化,特别是顺磁分量发生振荡变化引起的。 相似文献
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利用同步辐射角分辨光电子能谱研究了分子束外延生长的Co/Cu(111)超薄膜电子结构的变化.Cu(111)的位于表面布里渊区Γ点的表面态在覆盖度为两单层时仍然可以分辨,说明薄膜生长模式不是二维层状生长.在一单层和二单层时,动量沿Cu体布里渊区ΓΛL方向变化,Co的最明显的峰包有能量色散.在覆盖度从一单层到两单层的变化过程中,固定光子能量测谱发现Co的能带的能量调整.实验测得的Co膜的电子结构与已有理论计算的结果对比,初步确定Co原子在生长初期阶段为两层岛生长,而且在一单层时已经具有铁磁性. 相似文献
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系统地研究了Pt1-xCux/Co多层膜的结构与磁性.除了特定的x=0.10—0.15区间外,在Cu浓度区间x=0.04—0.30内,随着中介Pt层内Cu浓度的增加,导致各向异性Ku和剩余磁化强度Mr⊥的单调下降.这可能是由于Cu原子在Pt层中的无序造成的,使Pt的晶面场对称性发生局域畸变,从而引起上述参数的下降.在特定区域内,可能是形成了PtCu合金的有序相,此时晶场对Co原子的作用就像只有Pt原子一样.这是Cu掺入
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U. Pustogowa C. Blaas C. Uiberacker J. Zabloudil P. Weinberger L. Szunyogh C. Sommers 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,16(4):653-658
The magnetic properties of (ConPdm)r superstructures on Pd(100) and Pd(111) are evaluated using the fully-relativistic spin-polarized screened Korringa-Kohn-Rostoker
method. It is found that only in the case of a Pd(111) substrate such superstructures exhibit perpendicular magnetism, while
on a Pd(100) substrate the magnetization is oriented in-plane. Also investigated is the effect of interdiffusion in repeated
superstructures. By using the inhomogeneous coherent potential approximation (CPA) for layered systems the effect of ordering
into (repeated) superstructures can be described in an ab-initio-like manner. It is found that already small amounts of interdiffusion can be decisive for the actual value of the magnetic
anisotropy energy.
Received 3 November 1999 and Received in final form 18 January 2000 相似文献
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《Surface science》1986,172(2):363-371
Spin-polarized self-consistent localized-orbital (SCLO) calculations have been performed for a five-plane slab simulating Pd/Fe(100). Pd monolayers were placed in registry with both faces of a three-plane Fe(100) slab. We chose a PdFe bond length equal to the sum of metallic radii, 2.62 Å, and an FeFe bond length equal to the bulk value, 2.49 A. The computed energy bands for the Pd/Fe3/Pd slab resemble those calculated for a five-plane Fe(100) slab, except for a positive work-function shift of 0.5 eV. The Pd monolayer has a magnetic moment of 0.37μB/atom. The magnetic moment of an adjacent iron atom is 2.74μB, slightly smaller than the value 2.89μB at the surface of Fe5, but still significantly larger than the central-plane value 2.37μB. The d bands of the two metals are strongly hybridized, but very little charge transfer takes place across the interface. Compared with the isolated Pd(100) monolayer, or the clean Fe(100) slab, the surface density of states of Pd/Fe(100) is rather weak near the Fermi level, suggesting a reduced chemical reactivity for this surface. 相似文献
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《Journal of magnetism and magnetic materials》1991,95(2):L137-L141
(100) oriented FeCr and FeV films, 1000 Å thick, have been deposited on (100)Si using (100)Pd/Cu seed layers. Three compositions are made for each alloy, 75/25, 50/50 and 25/75, all show lattice spacings corresponding to a body-centered cubic structure. Magnetic measurement shows composition dependent magnetization: both FeCr and FeV with compositions of 75/25 and 50/50 are ferromagnetic, but not the ones with the composition of 25/75. In-plane magnetization along different crystalline axes shows the same crystalline anistropy as that of bulk Fe crystal for both 75/25 structures, with a higher magnetization along the [100] edge than the [110] one. For the 50/50 structures, the [100] edge shows a smaller magnetization at low fields than the [110] one, but exceeds the latter at higher field. The measured magnetizations are less than those from linearly diluted Fe lattices. The correlation between the structures and magnetic properties is discussed. 相似文献
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P. Le Fèvre H. Magnan D. Chandesris 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,10(3):555-562
The crystallographic structure of thin Ni films deposited on Cu(001) has been studied using Surface Extended X-ray Absorption
Fine Structure (SEXAFS). Taking advantage of the linear polarization of the synchrotron radiation, we have shown that Ni adopts
the Cu lattice parameter parallel to the interface. This lateral expansion induces a longitudinal compression of the unit
cell, leading to a face centered tetragonal structure of the Ni films from 3 to 10 monolayers. The temperature dependence
of the EXAFS oscillations has allowed to measure strain inside the Ni layers.
Received 22 December 1998 相似文献
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The structure and electronic properties of ultrathin Co films on W(1 1 0) grown by molecular beam epitaxy in UHV were investigated by low energy electron diffraction (LEED) and scanning tunneling microscopy and spectroscopy (STM and STS). For coverages above 0.7 ML the pseudomorphic (ps) monolayer is transformed gradually into close-packed (cp-) monolayer areas, showing up as separated islands that increase in size with coverage until the cp-monolayer is complete. Two different structures of the cp-monolayer were observed by atomically resolved STM, both leading to a 8 × 1 superstructure in the LEED pattern. Higher coverages continue to grow in the Stransky–Krastanov growth mode forming simultaneously double layer islands and triple layer islands in fcc(1 1 1) and hcp(0 0 0 1) stacking. STS reveals tunneling spectra that differ considerably depending on the thickness and on the structure. Two different classes of triple layer islands can be distinguished by a resonant peak at +0.3 eV appearing in only one of the two classes. We attributed this behavior to a different stacking according to a fcc or hcp structure. 相似文献
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利用第一性原理研究了覆盖度分别为1.00, 0.50和0.25 ML时CO分子单层膜在Cu(100)表面的吸附系统. 计算表明CO分子对不稳定. 获得了CO分子单层膜在虚拟Cu(100)表面的原子结构, 以及CO分子单层膜在Cu(100)表面吸附系统的原子结构. 当CO分子单层膜在Cu(100)表面的三个吸附位吸附, 覆盖度为1.00 ML时, 顶位和桥位都稳定, 而空心位不稳定; 覆盖度为0.50和0.25 ML时, 三个吸附位都稳定.比较吸附前后CO分子单层膜的原子结构, 可知CO分子和Cu(100)表面的相互作用强于CO分子单层膜之间的相互作用.
关键词:
CO分子单层膜
自组装
CASTEP
Cu(100) 相似文献
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We report the observation of bcc-like crystal structures in 2-4 monolayer (ML) Fe films grown on fcc Cu(100) using scanning tunneling microscopy. The local bcc structure provides a straightforward explanation for their frequently reported outstanding magnetic properties, i.e., ferromagnetic ordering in all layers with a Curie temperature above 300 K. The nonpseudomorphic structure, which becomes pseudomorphic above 4 ML film thickness, is unexpected in terms of conventional rules of thin film growth and stresses the importance of finite thickness effects in ferromagnetic ultrathin films. 相似文献