Electron Beam-assisted Synthesists, Structure and Luminescent Properties Porous Ceramics of MgAl2O4 and MgAlGaO4 Doped with Europium

Porous ceramics of MgAl2O4 (MAS) and MgAlGaO4 (MAGS) doped with europium were synthesized by ra- diation method. Radiation synthesis was performed with high efficiency within less than 1 s using radiation energy and mixture materials with no additives or any other materials used to promote synthesis. The synthe- sis method using a high-energy electron beam makes it possible to obtain refractory materials with high productivity, flexibly control the technological conditions of the process, and, accordingly, synthesize materi- als with desired properties. The structural properties of synthesized porous ceramics were investigated by X- ray diffraction (XRD-7000S diffractometer, Shimadzu), SEM. Results have shown that, the synthesized MAS have cubic structure and are in crystalline spinel MgAl2O4, while the synthesized double spinel MAGS con- tains two main phase components, MgAl2O4 and MgGa2O4. To study the luminescence properties of MAS and MAGS synthesized spinel doped with europium, photoluminescence measurements were performed. The photoluminescence spectrum of excitation of Eu3+ ions in spinel was monitored at λem = 615 nm (5D0→7F2). The PLE shows the f→f transition in the configuration of Eu3+ ions (at 393 nm (7F0→5L6), 463 nm (7F0→5D2)). The excitation band at 330 nm and 260 nm is characteristic of the charge transition between Eu3+ and O2- ions. The photoluminescence spectrum of the samples under excitation at 260 nm was studied. In the PL spectrum of spinel samples, the emission of Eu3+ ions are clearly visible. In the structure of the band with a maximum of 615, a peak is visible at 590 nm, characterized by the 5D0 → 7F1 transition. In the PL spectrum of samples, a weak spectral band appears with a maximum at 535 nm, characteristic of the emission of Eu3+ ions with the 5D1-7F1 transition. It is shown that the efficiency of radiation synthesis depends on the granulometric composition of the initial oxide powders.