Stabilization of moisture-reactive raw materials for improved synthesis of Ca-α-SiAlON:Eu~(2+) phosphor

摘要

The raw materials needed to make the Ca-α-SiAlON:Eu~(2+) phosphor contain highly moisture-reactive Ca_3N_2. Exposing them to a preheating process prior to high-temperature synthesis stabilized the raw materials against oxidation. Preheating above 1200 °C in a tube furnace directly connected to a glove box, resulted in the formation of intermediate phases such as CaAlSiN_3, which provided higher moisture resistance to the raw materials. We found that even after exposure to a humid environment, the preheated samples maintained PL characteristics similar to the conventional unexposed samples, while the PL intensity and particle homogeneity of the un-preheated samples were severely deteriorated.