2026/05/11 by David John, Shelja Sharma, Marius Stef +27
Chemistry · Materials Science · Physics and Astronomy · #Inorganic Fluorides and Related Compounds #Iron-based superconductors research #Luminescence Properties of Advanced Materials #cond-mat.mtrl-sci
paper · pdf · doi:10.1016/j.optmat.2026.118242
published as Optical Materials, 178 (2026), 118242
arxiv created 2026/05/11 · openalex publication_date 2026/06/10 · openalex created_date 2026/06/11 · arxiv updated 2026/08/04 · openalex updated_date 2026/08/04
Lanthanide-doped fluorides are promising materials for advanced photonic and quantum applications due to their wide bandgap, low phonon energy, and chemical stability. In this work, we present a systematic comparative study of ytterbium incorporation at low doping levels (0.05--0.2 mol%) in BaF2 and CaF2 single crystals, focusing on the interplay between host lattice properties, charge-state stabilization, and defect formation mechanisms. Using a combination of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), transmittance, and infrared photoluminescence (IR PL), we explore how host lattice properties affect the stabilization of Yb3+ and Yb2+ ions. XRD confirmed cubic phase purity and lattice parameter stability in both hosts, while XPS revealed surface chemical composition variations associated with charge-compensating defects and trace impurities. EPR spectra indicated that BaF2 favored perturbed Yb3+ environments with increasing dopant levels, while CaF2 maintained predominantly unperturbed sites, suggesting a more favorable ionic match for Yb2+. Photothermal deflection spectroscopy (PDS) and IR PL results showed host-specific optical responses, with CaF2 exhibiting crystal-field splitting and broader local field effects. These results reveal a clear decoupling between long-range structural stability and local lattice perturbations, and demonstrate that host cation identity governs the balance between Yb2+ and Yb3+ stabilization as well as defect-driven optical behavior. This offers valuable insights for optimizing rare-earth-doped fluoride crystals in laser, scintillator, and quantum device applications.