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 α-phase. The synthesized sample is irradiated with 120 MeV swift Au9+ ions for the fluence in the range from 1 × 1011 to 1 × 1013 ions cm−2. A broad photoluminescence (PL) emission with peak at ∼ 447 nm and two sharp emissions with peak at ∼ 679 and ∼ 695 nm are observed in pristine when sample was excited with 326 nm. However, in the irradiated samples the PL intensity at ∼ 447, 679 and 695 nm decreases with increase in ion fluence. The α-Al2O3 gives rise to seven Raman modes with Raman intensity with peaks at ∼ 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.