Multiplet resonance lifetimes in resonant inelastic X-ray scattering involving shallow core levels

TL;DR

This study improves the understanding of RIXS involving shallow core levels by incorporating self-consistent decay lifetime calculations, leading to better agreement between theory and experiment in transition metal oxides.

Contribution

The paper introduces a method to include self-consistently calculated decay lifetimes in RIXS modeling, enhancing the accuracy of theoretical predictions for shallow core level resonances.

Findings

Incorporating lifetime corrections improves data-theory agreement

Resonant elastic scattering shows Fano effect and shake-up response

Method enables quantitative predictions for RIXS spectra

Abstract

Resonant inelastic X-ray scattering (RIXS) spectra of model copper- and nickel-based transition metal oxides are measured over a wide range of energies near the M-edge (h$\nu$=60-80eV) to better understand the properties of resonant scattering involving shallow core levels. Standard multiplet RIXS calculations are found to deviate significantly from the observed spectra. However, by incorporating the self consistently calculated decay lifetime for each intermediate resonance state within a given resonance edge, we obtain dramatically improved agreement between data and theory. Our results suggest that these textured lifetime corrections can enable a quantitative correspondence between first principles predictions and RIXS data on model multiplet systems. This accurate model is also used to analyze resonant elastic scattering, which displays the elastic Fano effect and provides a rough upper bound for the core hole shake-up response time.