Luminescence characteristics of Sr₄Al₁₄O₂₅:Eu,Dy under proton irradiation

Fluorescence and long lasting emission properties of Sr₄Al₁₄O₂₅:Eu, Dy were examined under proton irradiation by varying incident energy. The fluorescence spectra have three strong peaks at 400, 480 and 570 nm. The first two peaks are attributed to the luminescence of Eu²⁺ and exhibit the long lasting property. The peak at 570 nm is attributed to the luminescence of Dy³⁺; it exhibits no luminescence after the irradiation has been stopped. The fluorescence intensity ratio of Eu²⁺/Dy³⁺ exhibits incident energy dependence, and its value increases with an increase in the proton energy. Radiation damages also exhibits incident energy dependence. Therefore, Sr₄Al₁₄O₂₅:Eu, Dy exhibits a potential of being employed to identify the incident proton energy. Long lasting emission has some decay time components and the longest one is unaltered by proton energy.