Ionoluminescence studies of natural kyanite mineral from different parts of Indian origin

Ionoluminescence (IL) studies of two natural kyanite (Al2SiO5) minerals collected from different regions of India was carried out using 120 MeV Ag9+ ions in the fluence range of 1.50–10.5 × 1011 ions/cm2. Identical emission peaks were observed in both the samples at ∼416, 463, 530–540 nm along with other emission peaks at ∼689 nm, 706 nm (sharp) and 770 nm (broad). The sharp emission peaks at 689 nm correspond to R lines of Cr3+ impurities and are related to transition of 2Eg → 4A2g. The sharp and broad emission peaks in the range of 706–770 nm are attributed to Fe3+ impurities and are related to the transition of 4T1g → 6A1g. The peak in the range of 530–540 nm is attributed to Mn2+ impurities and is related to the transition of 4T1 → 6A1. IL peak intensity decreases with the Ag9+ ion fluence which might be due to the thermal quenching/amorphization, caused by the ion beam irradiation. The amorphization in the sample was explained with the help of thermal spike model (TSM). These results demonstrated that IL is a very sensitive technique for impurity characterization and differentiating the origin of minerals.

Ionoluminescence spectra of natural kyanite irradiated with 120 MeV Ag9+ ions for (1) 1.50 × 1011 ions/cm2, (2) 3.00 × 1011 ions/cm2, (3) 4.5 × 1011 ions/cm2, (4) 6.0 × 1011 ions/cm2, (5) 7.5 × 1011 ions/cm2, (6) 9.0 × 1011 ions/cm2 and (7) 10.5 × 1011 ions/cm2.Figure optionsDownload as PowerPoint slideHighlights
► Natural kyanite (Al2SiO5) minerals of Indian origin have been analyzed by IL technique. 120 MeV Ag9+ ions in the fluence range of 1.50–10.5 × 1011 ions/cm2 was used.
► IL emission exhibits Cr3+, Fe3+ and Mn2+ impurities.
► IL peak intensity decreases with an increase of Ag9+ ion fluence due to quenching/amorphization. Amorphization in the sample was explained with the help of thermal spike model (TSM).