Polarization‐resolved Raman modes of monoclinic SrAl2O4 ceramics

SrAl2O4 materials were obtained by molten salt synthesis and sintered at high temperatures to produce a ceramic body suitable for polarization‐resolved Raman spectroscopy measurements. Optimized experimental conditions were employed to study the complex vibrational spectrum of these ceramics under polarized light. A reliable set of experimental bands was obtained: 69 Raman modes were in fact observed, out of the 81 bands foreseen for the stable monoclinic polymorph of the material, from which 38 could be assigned as totally symmetric A‐type modes, and 31 attributed as asymmetric B‐type ones. Significant differences between experimental data and theoretical predictions indicated that additional efforts are necessary to understand these two sets of vibrational information. The knowledge of the optical phonon features reported here can help to understand the exceptional luminescence properties of SrAl2O4 in its monoclinic phase. Polarization‐resolved micro‐Raman spectroscopic measurements were performed in SrAl2O4 ceramics. A reliable set of 69 Raman modes were observed, out of the 81 bands foreseen for the stable monoclinic polymorph of this material—38 totally symmetric (A‐type) modes could be assigned, whereas 31 bands could be attributed as asymmetric (B‐type) ones. The knowledge of the optical phonon features reported here can help to understand the exceptional luminescence properties of SrAl2O4‐based phosphors in its monoclinic phase.