EPR and optical studies of erbium-doped β-PbF2 single-crystals and nanocrystals in transparent glass-ceramics

• Published in: Physical chemistry chemical physics : PCCP 2007-01, Vol.9 (41), p.5591-5598
• Main Authors: DANTELLE, Géraldine, MORTIER, Michel, VIVIEN, Daniel
• Format: Article
• Language: English
• Subjects: Absorption; Ceramics - chemistry; Chemistry; Crystallization; Electron Spin Resonance Spectroscopy - methods; Erbium - chemistry; Erbium - classification; Exact sciences and technology; Fluorides - chemistry; General and physical chemistry; Lead - chemistry; Luminescence; Microscopy, Electron, Transmission; Nanoparticles - chemistry; Spectrophotometry - methods; X-Ray Diffraction
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/b706735f

beta-PbF(2) single-crystals and nanocrystals in transparent glass-ceramics doped with ErF(3) have been synthesized and studied with two complementary techniques: electron paramagnetic resonance (EPR) and optical spectroscopy (absorption, selective excitation, fluorescence). A comparative study shows that, in both single-crystals and glass-ceramics, Er(3+) ions occupy the same types of sites, leading to similar optical properties. An EPR investigation demonstrates that, in these materials, part of the Er(3+) ions occupy cubic symmetry sites. For these ions, we determine the crystal field splitting of the ground state (4)I(15/2) and the symmetry of its sublevels. We also provide evidence for the presence of another type of Er(3+) ions, not detectable by EPR but evidenced by optical spectroscopy. We clearly show that this Er(3+), which gives rise to up-conversion luminescence, corresponds to clusters associating Er(3+) and F(-) ions. In the single-crystals, the proportion of these two types of erbium ions is estimated. It strongly depends on the doping rate of the beta-PbF(2) crystals.