Resonant Inelastic X-ray Scattering of EuNi₂(Si_1-xGe_x)₂and Eu₂O₃at EuL₃Absorption Edge

Abstract

Bulk sensitive spectroscopies were performed for mixed valent compounds EuNi 2 (Si 1Àx Ge x ) 2 as a function of x, and Eu-sesquioxide (Eu 2 O 3 ), using techniques of high-resolution partial-fluorescence yield (PFY) and resonant inelastic x-ray scattering (RIXS) at the Eu L 3 absorption edge. The evolution of mean-valency as a function of chemical composition x in EuNi 2 (Si 1Àx Ge x ) 2 shows a drastic change between x ¼ 0:5 and 0.7. The experimental results also show a small amount of mixed valency for the end members, i.e., x ¼ 1 and 0 samples are also mixed valent. Single-impurity Anderson model calculations show good agreement with the PFY and RIXS experimental results, and thus provide a consistent set of electronic structure parameters. The composition controlled drastic change in meanvalence between x ¼ 0:5 and 0.7 is derived from a large hybridization change, consistent with the Kondo volume collapse picture.

Hybridization and suppression of superconductivity inCeFeAsO1−y: Pressure and temperature dependence of the electronic structure

“…The intensity of f 2 component is multiplied by 35. To extract the intensity ratios of the different f components we have analyzed the PFY-XAS and RXES spectra. [26][27][28][29][30][31] Figure 4 shows examples of the fits for ͑a͒ the PFY-XAS spectrum and ͑b͒ the RXES spectrum at E in = 5719 eV measured for SC CeFeAsO 1−y at 300 K. In the PFY-XAS spectra after subtraction of an arctangentlike ͑asymmetrical double sigmoid͒ function corresponding to the continuum excitations, two Voigt functions are used to fit the f 1 ͑Ce 3+ ͒ and the f 2 ͑Ce 2+ ͒ components. In the fit of the RXES spectra, we use a total of four Voigt functions for f 1 and f 2 .…”

“…To carry this out, we used two complementary hard x-ray spectroscopic probes at the Ce L 3 edge, partial fluorescence yield x-ray absorption spectroscopy ͑PFY-XAS͒ and resonant x-ray emission spectroscopy ͑RXES͒. [26][27][28][29][30][31][32] The PFY-XAS technique yields spectra with sharper features than conventional absorption, offering a higher accuracy when deriving quantitative information such as the valence. We find that both the SC and the non-SC samples show a gradual increase in the valence with pressure.…”

Temperature and pressure-induced valence transitions inYbNi2Ge2andYbPd2Yamaoka1, Jarrige2, Tsujii3 et al. 2010Phys. Rev. B486560View full textAdd to dashboardCite

“…[19][20][21][22][23][24][25] RXES yields truly bulk-sensitive information about the electronic structure. It is well suited to the study of subtle pressure-induced changes in the electronic state of rare-earth compounds.…”

Spin-split conduction band in EuB6and tuning of half-metallicity with external stimuli

“…Until now, however, applications of hard x-ray RIXS to study RE compounds have been limited to core excitations. 20 At RE L 3 -edges, RIXS probes 5d states directly, enabling one to study 5d related excitations. In particular, the 4f − 5d transitions in RE compounds provide information about the interaction between local moments and conduction electrons.…”