High transparency Cr,Nd:LuAG ceramics prepared with MgO additive

Cr (0.2 at.%) and Nd (0.8 at.%) co-doped Lu 3 Al 5 O 12 ceramics were fabricated with MgO as the sintering additive. The addition of a small amount of MgO can affect the grain boundary mobility and influence the number and location of micropores in ceramics during the sintering process. The results show that when the MgO content is 0.02   wt.%, high-transparency Cr,Nd:LuAG ceramics can be obtained by vacuum sintering at 1670   °C for 5   h followed by hot isostatic pressing (HIP) post-sintering at 1750   °C in an argon atmosphere ( P   =   200   MPa) for 5   h. The optimum in-line transmittance of the HIPed Cr,Nd:LuAG ceramics (3   mm thick) is 83.5% at a wavelength of 840   nm and 84.0% at 710   nm.