Single CaO accelerated densification and microstructure control of highly transparent YAG ceramic*

In this work, CaO single dopant was adopted to realize the densification and microstructure control of fine- grained YAG ceramic by a solid state reaction method and highly transparent YAG ceramics were obtained after vacuum sintering at 1820 $^{\mathrm{o}}$C. The average grain size was only 2.7 $\mu $m, when the amount of CaO used was 0.045 wt.{\%}. It was found that the CaO dopant promoted densification of YAG ceramics when the sintering temperature was lower than 1660 $^{\mathrm{o}}$C, however it dramatically inhibited grain growth when the sintering temperature was further increased.