title: Local heterogeneity for a Eu3+-doped glass evidenced by time-resolved fluorescence spectroscopy coupled to scanning near-field optical microscopy.
abstract: Time-resolved fluorescence spectroscopy (TRFS) was applied to an aluminate glass sample doped with Eu3+ cation as a fluorescent probe of the chemical environment and local symmetry. Conventional far-field experiments revealed the presence of two different phases: an amorphous phase featured by a highly disordered environment surrounding the Eu3+ cation and a more ordered polycrystalline phase that exhibits a significant increase in the Eu3+ fluorescence decay time compared to that of the amorphous phase. Near-field fluorescence spectra and decay kinetics were recorded in the frontier region between the two phases using a home-built scanning near-field optical microscope. SNOM-TRFS experiments confirmed the presence of local heterogeneities in this part of the glass at a sub-micrometric spatial scale. Polycrystalline sites featured an important shear-force interaction with the probing fiber optic tip, a longer fluorescence decay time, and a higher Stark splitting of the 5D0 --> 7FJ (J = 1-4) electronic transitions of the Eu3+ cations.
authors.affiliation: Laboratoire de Chimie Physique et Microbiologie pour l'Environnement LCPME, UMR CNRS-UHP 7564, 405, rue de Vandoeuvre, F-54600 Villers-Les-Nancy, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Grausem
authors.forename: Manuel
authors.initials: M
authors.lastname: Dossot
authors.forename: Sébastien
authors.initials: S
authors.lastname: Cremel
authors.forename: Bernard
authors.initials: B
authors.lastname: Humbert
authors.forename: François
authors.initials: F
authors.lastname: Viala
authors.forename: Patrick
authors.initials: P
authors.lastname: Mauchien