A new parameter for characterizing Eu3+ distribution in mixed‐valence Eu‐doped cubic LaF3‐based transparent glass‐ceramics.

Mixed‐valence Eu‐doped transparent oxyfluoride glass‐ceramics containing cubic LaF3 nanocrystals were fabricated by traditional melt‐quenching technique and consequent annealing processes. Their structural and luminescent properties were systemically investigated by X‐ray diffraction (XRD), transmission electron microscopy, absorption, excitation, emission spectra, and fluorescence lifetime measurements. Analyses of XRD patterns prove that the new precipitated nanocrystals disperse in glass‐ceramics crystallize in cubic LaF3. The spectroscopic investigations show that Eu2+ ions have been incorporated into the LaF3 nanocrystals preferentially, while Eu3+ ions still remain in the glass phase after crystallization. Based on the spectral results, a new parameter Rchange=RGC-RPG/RGC was defined to describe the changes of the environments of Eu3+ before and after crystallization more straightforwardly and more sensitively, where RPG and RGC represent the integrated intensity radio of 5D0 → 7F2 to 5D0 → 7F1 emissions of Eu3+ in PG and GC samples, respectively. Our investigation will not only enrich the understanding of fluoride nanocrystals‐based oxyfluoride glass‐ceramics, but also the distribution and luminescence behaviors of Eu3+ ions in them. [ABSTRACT FROM AUTHOR]