Photoluminescence and Raman studies in swift heavy ion irradiated polycrystalline aluminum oxide

Polycrystalline aluminum oxide is synthesized by combustion technique and XRD studies of the sample revealed the alpha-phase. The synthesized sample is irradiated with 120 MeV swift Au9+ ions for the fluence in the range from 1 x 10(11) to 1 x 10(13) ions cm(-2). A broad photoluminescence (PL) emission with peak at similar to 447 nm and two sharp emissions with peak at similar to 679 and similar to 695 nm are observed in pristine when sample was excited with 326 nm. However, in the irradiated samples the PL intensity at similar to 447, 679 and 695 nm decreases with increase in ion fluence. The alpha-Al2O3 gives rise to seven Raman modes with Raman intensity with peaks at similar to 253, 396, 417, 546, 630, 842, 867 cm(-1) observed in pristine. The intensity of these modes decreases with increase in ion fluence. However, the Raman modes observed at lower fluences are found to disappear at higher fluence.