Stabilization of novel high temperature phase yellow-emitting σ-type (Ba_{1-: X - Y}Eu_xMg_y)₂P₂O₇ phosphors using a melt synthesis technique

Novel Eu²⁺-activated phosphate phosphors based on high-temperature phase σ-Ba₂P₂O₇, which is an unstable phase at room temperature, were synthesized for the first time by a melt synthesis technique using an arc-imaging furnace. By doping Mg²⁺ into the host lattice, Eu²⁺-activated σ-Ba₂P₂O₇ phosphors were successfully obtained in a single phase form of a hexagonal structure and the emission intensity was also effectively enhanced. The relative emission peak intensity of the σ-(Ba_0.67Eu_0.03Mg_0.30)₂P₂O₇ phosphor was 315% of that for the σ-(Ba_0.97Eu_0.03)₂P₂O₇ phosphor. The emission color tunable from green emission with a peak at 516 nm to yellow emission with a peak at 551 nm can be achieved by controlling the Mg²⁺ content in the σ-(Ba_0.97-yEu_0.03Mg_y)₂P₂O₇ phosphors.