Measurement of f orbital hybridization in rare earths through electric dipole-octupole interference in X-ray Absorption Spectroscopy

Amélie Juhin (1) , Stephen F. Collins (2) , Yves Joly (3) , Maria Diaz-Lopez (4) , Kristina Kvashnina (5) , Pieter Glatzel (5) , Christian Brouder (1) , Frank de Groot (6)

1 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
2 DIAMOND Light source
3 NEEL - SIN - Surfaces, Interfaces et Nanostructures
4 NEEL - MRS - Matériaux, Rayonnements, Structure
5 ESRF - European Synchrotron Radiation Facility
6 Debye Institute for Nanomaterials Science

This work provides a direct route to measure the degree of hybridization of f states in rare earths. The interference between electric dipole and octupole transitions is measured at the L1 edge of Gd in Gd3Ga5O12 using X-ray Natural Linear Dichroism (XNLD) and high energy resolution fluorescence detection. The Gd 4f-6p admixture is quantified through the integral of the dipole-octupole XNLD using a new sum rule easily applicable to experimental data. The mixing of the Gd valence states with the O ligand orbitals, calculated from first-principles, reveals that despite their localized character, the Gd 4f orbitals mix with the O 2p and 2s orbitals with an antibonding and bonding character, respectively.

Domaines: Physique [physics]; Matière Condensée [cond-mat]

Amélie Juhin, Stephen F. Collins, Yves Joly, Maria Diaz-Lopez, Kristina Kvashnina, et al.. Measurement of f orbital hybridization in rare earths through electric dipole-octupole interference in X-ray Absorption Spectroscopy. Physical Review Materials, 2019, 3 (12), pp.120801(R). ⟨10.1103/PhysRevMaterials.3.120801⟩. ⟨hal-02361316⟩