Synthesis of Cerium α-SiAlON with Nuclei Addition

Cerium α-SiAlON ceramics were made from a powder mixture of Si₃N₄-AlN-CeO₂ that contained 1 wt% yttrium α-SiAlON powder. Plasma-activated sintering was used to examine the effect of the cooling rate on the formation of α-SiAlON. The formation of cerium α-SiAlON was suggested to be controlled by the nucleation at the surface of α-SiAlON nuclei, because α-phase formation could not occur without the addition of SiAlON powder. The solubility of cerium in the α-SiAlON was shown to be less than a previously predicted critical value.