| 초록 |
The fabrication of transparent ceramics via sintering in a vacuum is generally considered to generate the oxygen vacancies, and the following post-annealing and Hot Isostatic Press (HIP) procedure is inevitable to replenish the oxygen. Here, we fabricate the transparent yttria ceramics suppressing the formation of oxygen vacancies during vacuum sintering for the first time. The oxygen could be replenished via changing the Y2O3 powder bed to Y2O3/ZrO2 dual powder bed considering of thermodynamics. The oxygen-stabilized transparent Y2O3 ceramics are highly optical transparent compared to the conventional sinter-annealed one. Very interestingly, we could acheive theoretical value of transmittance for the as-sintered ceramics. Thermodynamic stabilization of the oxygen in the yttria ceramics is possible using the ZrO2 powder bed as an additional oxygen source. Moreover, both of the microstructure observation and the calculation results based on the Mie scattering theory indicate that the post-annealing cause pore develpoment at the grain boundaries deteriorating the optical property. This new approach is potentially applicable for the fabrication of other transparent ceramics. |
