Ionoluminescence studies of combustion synthesized Dy doped nano crystalline forsterite

Ionoluminescence (IL) of nano crystalline Mg₂SiO₄:Dy³⁺ pellet samples bombarded with 100 MeV Si⁺⁸ ions with fluences in the range (1.124–22.480) × 10¹² ions cm⁻² have been studied. Two prominent IL bands with peaks at ∼480 nm and ∼580 nm and a weak band with peak at ∼670 nm are recorded. The characteristic peaks are attributed to luminescence center activated by Dy³⁺ ions due to the transitions ⁴F_9/2→⁶H_15/2,⁶H_13/2 and ⁶H_11/2. It is found that IL intensity initially decreases rapidly and then continuous to decrease slowly with further increase in ion fluence. The reduction in the Ionoluminescence intensity with increase of ion fluence might be attributed to degradation of Si–O ( 2ν₃) bonds present on the surface of the sample and/or due to lattice disorder produced by dense electronic excitation under heavy ion irradiation.