Crystal structure, photoluminescence and cathodoluminescence of Ba1-xSrxAl2O4 doped with Eu2+

Herein we describe the synthesis, crystal structures, photoluminescence (PL) and cathodoluminescence (CL) spectra of phosphors in the Sr0.97-xBaxEu0.03Al2O4 system between x = 0 and x = 0.97. The syntheses of these phosphors were carried out by solid state reactions at 1350 degrees C in mixed gas (H-2/N-2). The molar fractions of the alkaline earth elements were varied in steps of 0.1. The Sr1-xBaxAl2O4 series manifested solid solutions of a monoclinic phase (at the Sr-rich side) and a hexagonal phase (at the Ba-rich side). At the Ba-rich side of Srx-1BaxAl2O4:Eu2+ we found evidence in the PL spectra that the hexagonal phase differed as the x(Ba) fraction changed: it changed at room temperature from the ferroelectric P6(3) structure at x(Ba) =1 to the paraelectric P6(3)22 phase at x(Ba)approximate to 0.9 and at x(Ba)approximate to 0.8 it went back to P6(3). Unlike the PL spectra, the CL spectra of the hexagonal phase of Sr0.97-xBaxEu0.03Al2O4 at x >= 0.5 indicated only the paraelectric P6(3)22 phase at room temperature. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.