Site-selective excitation of Eu3+ substituted sodium β″ alumina single crystals

Abstract
Broad band excitation spectra of Eu3+ substituted sodium β‘ alumina reveals that the Eu3+ ions occupy at least two distinct sites. Examination of the fluorescence spectrum excited by an ultraviolet laser (308 nm) reveals the presence of an additional site. 5D07FJ emission spectra characteristic of each site were obtained using site‐selective excitation. A crystal‐field analysis of the emission spectra thus obtained permits the assignment of these sites. The two inhomogeneously broadened 5D07F0 emissions at 569.4 and 576.7 nm are assigned as mid oxygen sites perturbed by various arrangements of the residual sodium ions, while the sharp 5D07F0 emission at 578.7 nm is assigned as the Beevers–Ross site.