Localized Character of4fElectrons inCeRhx

Ranju Jung

¹

,

Byung-Hee Choi

²

,

Seung Cheol Oh

³

et al.

Abstract

We have measured Ce 4f spectral weights of extremely alpha-like Ce transition metal intermetallic compounds CeRhx (x=2,3) and CeNix (x=2,5) by using the bulk-sensitive resonant photoemission technique at the Ce M5(3d(5/2)-->4f) edge. High energy resolution and longer escape depth of photoemitted electron at this photon energy enabled us to distinguish the sharp Kondo resonance tails at the Fermi level, which can be well described by the Gunnarsson-Schönhammer calculation based on the Anderson impurity Hamiltonian. On the other hand, the itinerant 4f band description shows big discrepancies, which implies that Ce 4f electrons retain localized characters even in extremely alpha-like compounds.

Electronic structure of semiconductingCeFe4P12: Strong hybridization and relevance of single-impurity Anderson model

“…It is surprising that the Ce 4f electronic states are similarly reproduced by both SIAM and LDA calculations, since these calculations are generally incompatible with each other. 36 The off-resonance PES spectrum is nicely reproduced by the calculated Fe 3d pDOS. The main peaks of the Fe 3d and Ce 4f appear at ϳ1 and ϳ0.7 eV, respectively, and this difference in the peak positions is in quantitative agreement with the Fe 3d and Ce 4f calculated pDOS.…”

Electronic structure ofCeRu2X2(X=Si,Yano1, Sekiyama2, Fujiwara3 et al. 2008Phys. Rev. BSelf Cite505210View full textAdd to dashboardCite

“…However, the f 0 contribution is about twice larger and the f 2 weight is apparently larger than for CeRu 2 Ge 2 . The f 1 contribution in the initial state is less than 0.9 but considerably larger than those for such strongly valence-fluctuating systems as CeT 2 (T = Fe, Rh, Ni, and Ir) 41,47,48 . We conclude that this "inbetween" value of the initial f 1 weight reflects the heavy fermion behavior and metamagnetic transition (localization of the 4f state) under high magnetic fields for CeRu 2 Si 2 .…”

Making use of x-ray optical effects in photoelectron-, Auger electron-, and x-ray emission spectroscopies: Total reflection, standing-wave excitation, and resonant effects

“…The relative numbers quoted here are furthermore very close to those given by 6ͱR, as discussed in the text following Eq. (37). The depth dependence shown here implies that the modulation of the electric field strength at the Bragg angle is strong enough to highlight a specific buried region, which is located as deep as 20 $ 30 Å below the surface for photoemission (with the limit being set by the IMFP for photoelectrons), and up to over 1000 Å for x-ray emission (with the limit set by the penetration depth of the x-rays).…”

“…As one specific example, the deconvolution of spectra so as to derive surface and bulk contributions has been a controversial issue in resonant x-ray photoemission spectroscopy (RPES) for cerium-based strongly correlated systems. [33][34][35][36][37] In this particular case, it has been recognized that the notion of x-ray optics is essential to understand high-resolution RPES more accurately and quantitatively because the photon energy is scanned through the absorption edges of cerium, with the x-ray penetration depth changing dramatically during such a scan. Another specific example of where modeling of x-ray optical effects is essential to understand the system is the characterization of multilayer film stacks and superlattices, which are ubiquitous in semiconductor technology, spintronic applications, and various energy conversion devices.…”