Electron paramagnetic resonance enhanced crystal field analysis for low point-group symmetry systems: C$_{2v}$ sites in Sm$^{3+}$:CaF$_2$/SrF$_2$

TL;DR

This study combines electron paramagnetic resonance and optical spectroscopy to analyze the crystal field in low-symmetry Sm$^{3+}$ doped fluorides, revealing detailed site geometries and dopant interactions.

Contribution

It introduces a comprehensive method integrating EPR and optical data to determine crystal-field parameters for C$_{2v}$ symmetry sites, advancing analysis of low-symmetry systems.

Findings

Determined unique crystal-field parameters for C$_{2v}$ sites.

Revealed site geometries and dopant interactions.

Enhanced understanding of low-symmetry crystal fields.

Abstract

We present a comprehensive spectroscopic study of C$_{2v}$ point-group symmetry sites in Sm$^{3+}$:CaF$_2$/SrF$_2$ codoped with either NaF or LiF. Data includes electron paramagnetic resonance measurements of Zeeman and hyperfine interactions for the ground state, as well as site-selective excitation and fluorescence spectroscopy up to the $^{4}$G$_{5/2}$ multiplet. Inclusion of the EPR data allowed us to determine unique crystal-field parameters. The parameters provide information about the geometry of the sites and the nature of the interactions between the Sm$^{3+}$ dopant and the alkaline earth co-dopant.