Sol–gel synthesis of micro and nanocrystalline BaAl2O4:Eu3+ powders and their luminescence properties

The crystal structure of BaAl2O4 consists of corner-connected AlO4 tetrahedra and Ba ions are situated in the channels of this sub-structure. According to this report the P63 structure was not found. Finally, it has been found a direct evidence for broken hexagonal (P6322) symmetry in the form of small nano-domains of the structure and the BaAl2O4 was refined with a orthorhombic, P212121 crystal system. [Display omitted] •Sol–gel method was successfully applied to obtain an orthorhombic BaAl2O4 doped with Eu3+ ions.•Prepared compound structures were confirmed by X-Ray diffraction and TEM analysis.•Unusual spectroscopic properties appeared in luminescence spectra were described.•A detailed analysis of the luminescence spectra by the Judd–Ofelt theory has been performed. In this paper, we report the obtention of barium aluminate (BaAl2O4) powders doped with Eu3+ ions by the sol–gel method heat-treated at 900 and 1000°C for 3h. XRD patterns indicated that the powders have orthorhombic structure with a high crystallite dispersion. The powders have size at submicron scale. They are a strong red emitting materials when are irradiated by ultraviolet light (250nm). Measured emission and excitation luminescence spectra demonstrated characteristic spectroscopic properties of Eu3+ ions. Recorded luminescence decays and emission spectra were base for calculation of Judd–Ofelt intensity parameters. A detailed analysis of calculated parameters in connection with observed structural and spectroscopic measurements has been done and described.