Microstructure evolution during reactive sintering of Y3Al5O12:Nd3+ transparent ceramics: Influence of green body annealing

Abstract The effect of green bodies’ mesostructure on the porosity, optical properties and laser performance of reactive sintered Y 3 Al 5 O 12 :Nd 3+ transparent ceramics was studied. Only minor changes in microstructure were revealed for green bodies without annealing and those annealed at 600, 800, 1000 °C, while average pore size increases to 140 nm for sample annealed at 1200 °C. Y 3 Al 5 O 12 :Nd 3+ ceramics sintered at 1750 °C for 10 hours possess significant differences in the final porosity, optical and laser characteristics. Despite all green bodies exhibit a similar phase evolution and sintering behavior on heating, the differences appear in the final stage, when the latest percentage of porosity is removed. The green bodies annealed at 600 °C have an optimal mesostructure from the standpoint of uniform densification. Y 3 Al 5 O 12 :Nd 3+ ceramics prepared using these green bodies exhibit porosity ≤0.001 vol% and yield efficient laser emission at 1.06 μm with slope efficiency as high as 67% in quasi-continuous pumping at 807 nm.