Sintering of Transparent Y₂O₃ by Vacuum Hot Presing and Its Spectroscopic Properties

Abstract

In this experiment, vacuum hot pressing (VHP) was applied in order to get the transparent Y₂O₃. where LiF. NaF or NH₄F was added as the sintering additive. Transparent Y₂O₃ was obtained by LiF addition under following UP conditions: temperature 1573K. pressure 400kgf/cm², vacuum 10^-4Torr. sintering time 2h. In the case of NaF or NH₄F, however, the transparent Y₂O₃ was not obtained, where the residual F(fluorine) was detected by EPMA in the opaque region. Much more homogeneous structure was observed in the transparent Y₂O₃ than the opaque one, and it was also confirmed that the grain size is larger in the former than the latter.