Abstract The 4f surface versus bulk electronic structure of three strongly hybridizedCe intermetallic compounds (CeCo 2 , CeRh 2 and CeRh 3 ) is investigated by exploiting the 4f photoemission resonant enhancement at the Ce 3d–4f and Ce 4d–4f thresholds. The much higher surface sensitivity at the shallow 4d threshold allows to extract the surface and bulk 4f electronic structure. Our results show
Abstract Surface effects are detected between the fspectralfunctions obtained from UV and X-ray inverse photoemission spectra of a number of Cecompounds. They are: a variation of the I( f 1 ) I( f 2 ) intensity ratio, which indicates the presence of a less hybridizedsurface layer compared to the bulk, and a surface-to-bulk shift of the f2 component, which is larger than the expected surface core level
摘要 在从许多 Ce 化合物的 UV 和 X 射线逆光发射光谱获得的 f 光谱函数之间检测到表面效应。它们是: I( f 1 ) I( f 2 ) 强度比的变化,表明与本体相比存在杂化程度较低的表面层,以及 f2 分量的表面到本体偏移,即大于在同构 Lu 化合物上测得的预期表面核能级偏移。额外的偏移(高达 0.3 eV)被解释为与理论计算一致的杂交效应。绘制了对表面现场 ff 相关能的一些影响。
Study of bulk ground state properties of cerium intermetallics by linear dichroism in 4f resonant inelastic X-ray scattering
integrated along the emitted energies, and the radius of the cerium ion in different compounds. Since the atomic size of cerium is directly related to its valence, we conclude that the linear dichroism in inelastic X-ray scattering is a bulk-sensitive indicator of the relative weight of the 4f 0 and 4f 1 ground state configurations of ceriumcompounds.
摘要 我们通过 4f 共振非弹性 X 射线散射在铈的金属间化合物(CeRh 2 、CePd 3 、Ce 7 Rh 3 和 CeAl 2 )的 M 5 区测量了极化效应。使用方向垂直或平行于散射平面的线偏振辐射进行实验。二向色性强,取决于化合物的杂交程度。我们表明,沿发射能量积分的测量二色性与不同化合物中铈离子的半径之间存在单调关系。由于铈的原子大小与其化合价直接相关,因此我们得出结论,非弹性 X 射线散射中的线性二色性是铈化合物 4f 0 和 4f 1 基态构型相对重量的体敏感指标。
Surface effects on the 4f hybridization in Ce intermetallics as seen with Ce 3d XPS
作者:L. Braicovich、L. Duò、P. Vavassori、G.L. Olcese
DOI:10.1016/0039-6028(95)00337-1
日期:1995.7
hybridizedcompounds (CeRh 2 and CeRh 3 ) the reduction of the hybridization at the surface is well seen while Ce 7 Rh 3 which is weakly hybridized has little, if any, surface effect. In order to quantify the effect we introduce a suitable procedure in data analysis. The ground state properties in the bulk and at the surface are briefly discussed by using the single impurity Anderson Hamiltonian
我们展示了使用 Al K α 和 Mg K α X 射线拍摄的 Ce 7 Rh 3 、CeRh 2 和 CeRh 3 的 Ce 3d XPS 结果。Mg 激发的光谱比 Al K α 激发的光谱对表面更敏感,并且利用光谱函数的差异来获得通过 Ce 中的多重态结构所见的本体和表面 4f 构型变化的信息3d XPS。在强杂交化合物(CeRh 2 和CeRh 3 )中,可以清楚地看到表面杂交的减少,而弱杂交的Ce 7 Rh 3 几乎没有表面效应(如果有的话)。为了量化效果,我们在数据分析中引入了一个合适的程序。使用单杂质安德森哈密顿量简要讨论了体中和表面的基态性质
A cerium M-edge X-ray absorption study of the CeM2 compounds, where M is Mg, Al, Fe, Co, Ni, Ru and Rh
作者:F. Grandjean、G.D. Waddill、T.R. Cummins、D.P. Moore、Gary J. Long、K.H.J. Buschow
DOI:10.1016/s0038-1098(98)00404-9
日期:1998.10
The cerium valence in the CeM2 compounds, where M is magnesium, aluminum, iron, cobalt, nickel, ruthenium and rhodium, has been measured at room temperature by X-ray absorption at the cerium M-edge. The observed valencies, which agree with previous more limited measurements made at the cerium L-III-edge, extend the study to additional compounds and lead to the conclusion that the relationship between the cerium volume and its valence in the CeM2 compounds is not straightforward. The results show a clear linear increase in the cerium valence with the atomic number of the metal M and indicate that the increase in the cerium valence from 3.05 in CeMg2 to 3.24 in CeRh2 results from an increase in the hybridization between the cerium 4f orbitals and the highest occupied M orbitals. (C) 1998 Elsevier Science Ltd. All rights reserved.