Transition intensities of trivalent lanthanide ions in solids: Revisiting the Judd-Ofelt theory

TL;DR

This paper introduces a modified Judd-Ofelt theory for trivalent lanthanide ions in solids, combining atomic-structure calculations with adjustable parameters to better predict transition intensities, exemplified by europium.

Contribution

The authors develop a new model that improves the prediction of lanthanide ion transition intensities by integrating atomic calculations with crystal-field parameters.

Findings

Successfully applied to Eu$^{3+}$, reproducing experimental data.

Provides physical insights into all transitions within the ground state.

Enables interpretation of polarized-light transitions.

Abstract

We present a modified version of the Judd-Ofelt theory, which describes the intensities of f-f transitions by trivalent lanthanide ions (Ln$^{3+}$) in solids. In our model, the properties of the dopant are calculated with well-established atomic-structure techniques, while the influence of the crystal-field potential is described by three adjustable parameters. By applying our model to europium (Eu$^{3+}$), well-known to challenge the standard Judd-Ofelt theory, we are able to give a physical insight into all the transitions within the ground electronic configuration, and also to reproduce quantitatively experimental absorption oscillator strengths. Our model opens the possibility to interpret polarized-light transitions between individual levels of the ion-crystal system.