Local Structure and L₁- and L₃-Edge X-ray Absorption Near Edge Structure of Late Lanthanide Elements (Ho, Er, Yb) in Their Complex Oxides

Abstract

Characteristic features of Ho, Er, and Yb L 1 -edge and L 3 -edge XANES spectra of their various complex oxides were investigated to find a relationship to the local configuration around these late lanthanide atoms. A pre-edge peak area of the L 1 -edge or a full width at half-maximum of the white line of the L 3 -edge XANES spectra have a significant correlation with an abstract geometrical index defined by bond angles formed by a center atom, Ho, Er, or Yb, and two adjacent oxygen atoms, which acts as an indicator of disorder of the local configuration. Theoretical calculation based on multiple scattering theory revealed a general trend of the pre-edge peak at Ln L 1 -edge XANES spectra and the broadening of the white line of Ln L 3 -edge XANES spectra. This finding will open a way to analyze the local structure of late lanthanide elements by means of XANES spectroscopy.

Local Structure Study of Lanthanide Elements by X‐Ray Absorption Near Edge Structure Spectroscopy

“…We also examined the relationship between the local structure and the L 1 ‐edge and L 3 ‐edge features of various oxides with early (Pr, Nd, Sm) and late (Ho, Er, Yb) lanthanide elements. These Ln L 1 ‐edge and L 3 ‐edge XANES spectra also show small but significant pre‐edge and white line features, and the BAA index works well with the experimental parameters from the L 1 and L 3 ‐edge XANES spectra as shown on the Ln L 1 ‐edge in Figure . Please refer to our previous paper for the corresponding L 3 ‐edge data.…”

“…8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 These Ln L 1 -edge and L 3 -edge XANES spectra also show small but significant pre-edge and white line features, and the BAA index works well with the experimental parameters from the L 1 and L 3 -edge XANES spectra as shown on the Ln L 1 -edge in Figure 6. [28][29] Please refer to our previous paper for the corresponding L 3 -edge data. 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52…”

“…We started La L 1 and L 3 ‐edge XANES measurement of well‐defined La complex oxides and found a simple correlation among the pre‐edge feature at the L 1 ‐edge, the white line width on the L 3 ‐edge, and the local symmetry of the Ln species itself, and proposed a simple index, a bond angle analysis (BAA) index defined from all of the independent angles consisting of an X‐ray absorbing atom and two adjacent O atoms. Next, we successfully demonstrated generality of this strategy for Pr, Sm, Nd, and Ho, Er, Yb complex oxides. These results suggest that the empirical quantitative analysis on the Ln L 1 and L 3 ‐edge XANES spectra could be a complementary method to conventional EXAFS curve fitting analysis.…”

Measurement of f orbital hybridization in rare earths through electric dipole-octupole interference in x-ray absorption spectroscopy

“…XAS measures the transition probability for a core electron of an absorbing ion to be promoted into unoccupied electronic states, which is mainly achieved by electric dipole ( = 1) E 1 transitions and in second order by electric quadrupole ( = 2) E 2 transitions. XAS provides insight into the local electronic structure of the absorber, including valency, ligand-metal covalency, or on-site mixing of atomic orbitals, as has been demonstrated in rare-earth compounds using both ligand and rare-earth absorption edges (e.g., [7][8][9][10][11][12][13][14][15]). Over the years, the technique has been popularized under different forms, amongst which, x-ray magnetic circular and linear dichroism (XMCD [16,17] and XMLD [18]), x-ray natural circular and linear dichroism (XNCD [19] and XNLD [20]), exploiting the dependence of XAS upon the polarization state and/or the direction of the incident x rays to reveal anisotropy in charge, orbital, or spin distribution, or the mixing between electronic states with different parity.…”

Probing the effect of radiation damage on the structure of rare-earth phosphates

“…The white-line feature in the La L3-edge spectra represents a 2p à 5d excitation [61]. After ion-implantation, the intensity of the La L3-edge decreased relative to the as-synthesized material and the spectra became broader [61,62]. This observation suggests a distortion of the La coordination environment in the ion-implanted materials (Figures 11a and 11b) [61,62].…”