FLUORESCENT MATERIAL FOR AUTHENTICITY ASSESSMENT, AND AUTHENTICITY ASSESSMENT MEANS

摘要

Provided is a blue light-emitting fluorescent material for authenticity assessment wherein it is possible to emit visible light having a luminescence intensity which is high enough to be sufficiently seen by the naked eye even if the intensity of the emitted light is relatively weak such as an infrared ray, and the emission period is a period which is long enough to be sufficiently seen by the naked eye. The fluorescent material for authenticity assessment is represented by the formula (Sr_2-x-yEu_xTm_y)Al_2mMg_n-mSi_2n-mO_2+5n, wherein x is 0.0025≤x≤0.05, y is 0.01≤y≤0.07, m is 0≤m≤0.008, and n is 0.97≤n≤1.4. As a consequence, the fluorescent material for authenticity assessment emits visible light which can be sufficiently seen by the naked eye even if the light emitted is an infrared ray which has a relatively low intensity.