Fluorescence Line Narrowing study of Cr3+ ions in cordierite glass nucleating MgAl2O4 nanocrystals

The luminescence of Cr3+ ions in cordierite glass nucleating MgAl2O4 nanocrystallites has been investigated. The time resolved fluorescence line narrowing measurements and the temperature dependence of the homogeneous line width show that most Cr3+ ions are inside the nanocrystallites. Cr3+ ions occupy non-equivalent crystal sites, due to the Mg2+-Al3+ inversion effect. The values of the homogeneous line width compare well with those of previous studies in crystals. No surface effect has been observed due to the large size of the crystals.