INFLUENCE OF CERIUM CONCENTRATION AND SINTERING ATMOSPHERE ON THE PHASE COMPOSITION AND LUMINESCENT PROPERTIES OF Y2.98-хCeхAl5.02О12 CERAMICS

The phase composition and spectral-luminescent properties of ceramic samples obtained from oxide compositions with the general formula Y2.98-хCeхAl5.02О12 (x = 0.05, 0.10, 0.20, 0.30, 0.45, 0.60 formula units (f.u.)) were investigated. It was found that the phase composition of the ceramic powders depended significantly on the concentration of cerium and the calcination atmosphere. The maximum concentration of cerium cations in the garnet lattice was determined to be approximately 0.1 f.u. when calcined in air, and approximately 0.16 f.u. when calcined in the argon – hydrogen atmosphere. The photoluminescence of the ceramic samples was studied when excited by a laser with a wavelength of 445 nm. It was observed that ceramic samples sintered in argon and hydrogen had a higher luminescence intensity compared to samples synthesized in a vacuum. The possibility of shifting the wavelength of the maximum luminescence intensity from 546 nm to 570 nm by changing the cationic composition and sintering conditions of the ceramics was demonstrated. Additionally, the negative effect of oxidative annealing of ceramic samples on the intensity and position of luminescence maxima in Y2.98-хCeхAl5.02О12 oxide compositions heavily doped with cerium was shown.