We have examined the potential of Lg 4 emission spectroscopy as a new method for valence determination.Sm Lg 4 emission spectra of a mixed valence compound, SmB 6 , as well as Sm standard references were recorded using a multicrystal, multidetector spectrometer at 298 K. The Lg 4 spectra exhibited a large chemical shift ($4.5 eV) and substantial profile changes depending on the Sm oxidation state. Splitting of the Sm Lg 4 band was attributed to spin-dependent atomic multiplets, and valence-dependent edgeshifts of the Sm L I XANES spectra strongly suggest that the chemical shift of the Lg 4 emission is mainly due to the screening effects of the Sm L I core. The Lg 4 spectrum of SmB 6 was well reproduced by the averaged spectra of SmS and SmF 3 , indicating a SmB 6 valence of 2.65 AE 0.03. The advantages of the Lg 4 method, including simple data treatment and no need for an excitation energy scan, will encourage its use in several areas of materials science.

We report a resonant inelastic x-ray scattering (RIXS) study of crystalline CeB(6). Ce L(α1,2) RIXS was measured with excitation energies resonant with the Ce L(3)-edge. A lifetime-broadening suppressed x-ray absorption near-edge structure (LBS-XANES), which successfully reproduced the L(α1,2) RIXS spectra over wide ranges of excitation and emission energies, was simulated using the SIM-RIXS program. A pre-edge structure in the LBS-XANES can be resolved, and many-body effects were suggested in the L(α1,2) RIXS around the Ce L(3)-edge energy. No convincing signs of Ce (II) or Ce (IV) states were observed in the LBS-XANES. Ce L(γ4) RIXS was measured at 302 K and 28 K with excitation energies across the Ce L(1)-edge. The interactions of p-valence electrons between Ce and B(6) were found to be considerably small, regardless of temperature. Thus, the electronic state of CeB(6) was concluded to be suitably described as a nominally Ce(4f(1))(3+)(e(-))(B(6))(2-) system with some hybridization among all valence orbitals of Ce and B.

No abstract

Ga 9 with a resolution of~0.9 eV. Peak splitting of the YbLg 4 line was observed in all the recorded spectra and was attributed to the two components originating from the LS coupling of the Yb5p hole, the 0 spectra of the mixed valence intermetallics, i.e. YbNi 3 Ga 9 (v = 2.59) and b-YbAlB 4 (v = 2.75), were fairly well reproduced by averaging the spectra of divalent Yb and trivalent YbNi 3 Al 9 , which suggests the possibility of using the YbLg 4 emission for determining the valence of Yb intermetallics. In trivalent Yb compounds, the relative intensity of Lg 4 compared with that of Lg 4 0 , as well as the appearance of a high-energy satellite, was found to be influenced by the ligands around the Yb ions. With the aid of preliminary atomic multiplet and band structure calculations, the differences in the valence band structure and resultant screening effects on the O II,III À1 states were determined to be the possible causes for the observed ligand dependence.

No abstract