Luminous material and method for preparing the same

The present invention relates to an europium-activated alkaline earth metal aluminate luminous material. The europium-activated alkaline earth metal aluminate luminous material is characterized in that the afterglow brightness thereof (Y 23 DEG C and 120 min) exhibited 120 min after photo-irradiation discontinuation at 23 DEG C is at least 0.007 Cd/m2, and that the temperature dependence (TD) of afterglow brightness expressed by the ratio of afterglow brightness thereof (Y 80 DEG C) exhibited 10 min after photo-irradiation discontinuation at 80 DEG C to afterglow brightness thereof (Y 23 DEG C) exhibited 10 min after photo-irradiation discontinuation at 23 DEG C, Y 80 DEG C/Y 23 DEG C, is at least 1. This luminous material realizes prolonged afterglow and further exhibits thermoluminescence over a wide temperature range even without the use of an expensive rare earth element, such as dysprosium, as a co-activator. Thus the material can be used over a wide temperature range and the environment for use of the m