| abstract |
A fluorescent substance having a high quantum efficiency and satisfactory temperature characteristics, and a process for producing the fluorescent substance.nThe fluorescent substance is a Sialon-type oxynitride fluorescent substance which comprises an inorganic compound having a composition comprising a metallic element (M), aluminum, silicon, and one of oxygen and nitrogen or both, part of the metallic element (M) having been replaced with an element (R) serving as an emission center. The sustance has a low paramagnetic defect density. This fluorescent substance can be obtained by heat-treating a raw-material mixture in a nitrogen atmosphere to obtain an intermediate fired product and heat-treating the intermediate fired product in a mixed nitrogen/hydrogen gas atmosphere. |