The scandium impact on the sintering of YSAG:Yb ceramics with high optical transmittance

Optical ceramics based on Yb2O3-Y2O3-Sc2O3-Al2O3 solid solutions with a garnet structure were obtained using chemical precipitation and vacuum sintering techniques. In the samples' composition, scandium was incorporated into both dodecahedral and octahedral garnet sites in ratios from 4 : 1 to 1 : 4. The differential thermal analysis and dilatometry methods were used to study the phase transformations kinetics of the precursor powders and the vacuum sintering kinetics of YSAG:Yb compacts. It was found that the garnet cationic composition has a strong effect on the optical ceramics' sintering temperature ranges. It was also pointed out that an increase in the scandium content in the dodecahedral YSAG:Yb garnet site was accompanied by a decrease in the vacuum sintering temperature, which ensures maximum compaction rate. For the samples with the Y2.15Yb0.25Sc1.00Al4.6O12, Y2.35Yb0.25Sc1.00Al4.4O12, Y2.55Yb0.25Sc1.00Al4.2O12, Y2.52Yb0.25Sc0.38Al4.85O12 compositions, optical transmission in visible and near-infrared range of more than 80% was achieved.