INVESTIGATION OF THE KINETICS OF VACUUM SINTERING OF OPTICAL LUMINESCENT CERAMICS Y3-xScxA5O12:Cr

The purpose of this work is to study the effect of scandium in the dodecahedral and octahedral positions of the garnet crystal lattice on the features of vacuum sintering of optical ceramics Y3-хScxAl2-yScyAl3O12:Cr, as well as on its optical and luminescent properties. YSAG:Cr optical luminescent ceramics were manufactured for the first time from ceramic powders of metastable compositions with a high scandium content in a dodecahedral position. The considered compositions were described by the general formula Y3-хScxAl2-yScyAl3O12, where 0,12 ? x ? 1,50 and 0,08 ? y ? 1,00 f. u. with a total scandium content from 0.12 to 1.70 f. u. The following studies of YSAG:Cr: ceramic samples were carried out: X-ray diffractometry, measurement of the shrinkage kinetics of ceramic compacts by dilatometry, study of the morphology and elemental composition of the ceramic surface by scanning electron microscopy (SEM). The light transmission and luminescence spectra were measured. It is shown that ceramics made from compositions with a predominant scandium content in the dodecahedral position reach maximum density at lower temperatures compared to compositions containing a greater amount of scandium in octahedral positions. It was found that with an increase in the sintering temperature of YSAG:Cr ceramics compositions with a high scandium content in the dodecahedral position become unstable.