Luminescence channels of manganese-doped spinel

Abstract Two independent luminescence channels are observed from manganese-doped spinel Mn:MgAl 2 O 4 . The luminescence around 520 nm is assigned to transition from the lowest electronic excited state 4 T 1 to the ground state 6 A 1 of Mn 2+ (3d) 5 ion by analyzing the excitation spectrum and electron spin resonance measurement. The emission at 650 nm is triggered by the band edge excitation and is assigned similarly to the charge-transfer process associated with the manganese ion.