Spectroscopy of high-energy states of lanthanide ions

TL;DR

This paper reviews recent advances in spectroscopic analysis of high-energy lanthanide ion states, emphasizing ab-initio calculations and excited-state absorption techniques to understand electronic structures.

Contribution

It introduces new computational methods and experimental approaches for probing the 4f$^{N-1}$5d states of lanthanide ions in host materials.

Findings

Ab-initio calculations estimate crystal-field and spin-orbit parameters for Ce$^{3+}$.

Excited-state absorption can probe electronic and geometric structures.

Calculations for Yb$^{2+}$ illustrate potential applications.

Abstract

We discuss recent progress and future prospects for the analysis of the 4f${N-1}$5d excited states of lanthanide ions in host materials. Ab-initio calculations for Ce$^{3+}$ in LiYF$_4$ are used to estimate crystal-field and spin-orbit parameters for the 4f$^1$ and 5d$^1$ configurations. We discuss the possibility of using excited-state absorption to probe the electronic and geometric structure of the 4f$^{N-1}$5d excited states in more detail and we illustrate these ideas with calculations for Yb$^{2+}$ ions in SrCl$_2$.