Ion beam-induced luminescence and photoluminescence of 100 MeV Si8+ ion irradiated kyanite single crystals

lonoluminescence (IL) of kyanite single crystals during 100 MeV Si8+ ion irradiation has been studied in the fluence range 1.87-7.50 x 10(11) ions/cm(2). Photoluminescence (PL) of similar dimensional crystals was recorded with same ions and energy in the fluence range 1 x 10(11) -5 x 10(13) ions/cm(2) with an excitation of 442 non He-Cd laser beam. A sharp IL and broad PL peaks at similar to 689 and 706 run were recorded. This is attributed to luminescence centers activated by Fe2+ and Fe3+ ions. It is observed that up to a given fluence, the IL and PL peak intensities increase with increase of Si8+ ion fluence. The stability of the chemical species was Studied on with and without irradiated samples by means of FT-IR spectroscopy. The results confirm that the O-Si-H type bonds covering on the surface of the sample. This layer might be acting as a protective layer and there by reducing the number of non-radiative recombination centers. (c) 2008 Elsevier Ltd. All rights reserved

Swift heavy ion induced thermoluminescence studies in polycrystalline aluminum oxide

When energetic swift heavy ions interact with matter, inelastic collision (leading to electronic energy loss-Se) and elastic collision (leading to nuclear energy loss -Sn) take place. In the present study, the effect of energetic ion species on thermoluminescence (TL) of polycrystalline aluminum oxide (PAO) is reported. PAO pellets of 6 mm diameter are irradiated with energetic Au9+, Ni7+ and Si7+ ions for the fluence of 1×1013 ions cm-2. A single well resolved prominent TL glow with peak at 538 K is observed in Si7+ irradiated samples. However, in Ni7+ and Au9+ irradiated samples a prominent TL glow with peak at 610 K along with a shoulder at 513 K is observed. On the other hand, when PAO samples are irradiated with g-rays two well separated TL glows with peaks at 483 K and 638 K are observed. A prominent PL emission with peak at 430 nm besides a weak emission with peak at 480 nm and a shoulder at 525 nm are observed in 120 MeV Au9+ion irradiated samples when excited with 320 nm. These PL peaks are attributed to F, F2+ and F22+-centers respectively. However, in Si7+ irradiated samples a single PL emission peak at 430 nm is observed and it is attributed to F-centers

Thermally stimulated luminescence studies in combustion synthesized polycrystalline aluminum oxide

Synthesis of materials by combustion technique results in homogeneous and fine crystalline product. Further, the technique became more popular since it not only saved time and energy but also was easy to process. Aluminum oxide phosphor was synthesized by using urea as fuel in combustion reaction. Photoluminescence (PL) and thermally stimulated luminescence (TSL) characteristics of γ-irradiated aluminum oxide samples were studied. A broad PL emission with a peak at ∼ 465 nm and a pair of strong and sharp emissions with peaks at 679 and 695 nm were observed in γ-rayed samples. The PL intensity was observed to increase with increase in γ-ray dose. Two prominent and well resolved TSL glows with peaks at 210°C and 365°C were observed in all γ-irradiated Al2O3 samples. The TSL intensity was also found to increase with increase in γ-ray dose. The TSL glow curves indicated second order kinetics

Luminescence studies on swift heavy ion irradiated nanocrystalline aluminum oxide

Pellets of nanocrystalline aluminum oxide synthesized by a combustion technique are irradiated with 120 MeV Au9+ ions for fluence in the range 5 x 10(11)-1 x 10(13) ions cm(-2). Two photoluminescence (PL) emissions, a prominent one with peak at similar to 525 nm and a shoulder at similar to 465 nm are observed in heat treated and Au9+ ion irradiated aluminum oxide. The 525 nm emission is attributed to F-2(2+)-centers. The PL intensity at 525 nm is found to increase with increase in ion fluence up to 1 x 10(12) ions cm(-2) and decreases beyond this fluence. Thermoluminescence (TL) of heat-treated and swift heavy ion (SHI) irradiated aluminum oxide gives a strong and broad TL glow with peak at similar to 610 K along with a weak shoulder at 500 K. The TL intensity is found to increase with Au9+ ion fluence up to 1 x 10(13) ions cm(-2) and decreases beyond this fluence. (C) 2010 Elsevier B.V. All rights reserved

Thermally stimulated luminescence studies in combustion synthesized polycrystalline aluminum oxide

Synthesis of materials by combustion technique results in homogeneous and fine crystalline product. Further, the technique became more popular since it not only saved time and energy but also was easy to process. Aluminum oxide phosphor was synthesized by using urea as fuel in combustion reaction. Photoluminescence (PL) and thermally stimulated luminescence (TSL) characteristics of γ-irradiated aluminum oxide samples were studied. A broad PL emission with a peak at ∼ 465 nm and a pair of strong and sharp emissions with peaks at 679 and 695 nm were observed in γ-rayed samples. The PL intensity was observed to increase with increase in γ-ray dose. Two prominent and well resolved TSL glows with peaks at 210°C and 365°C were observed in all γ-irradiated Al2O3 samples. The TSL intensity was also found to increase with increase in γ-ray dose. The TSL glow curves indicated second order kinetics

Swift heavy ion induced thermoluminescence studies in polycrystalline aluminum oxide

When energetic swift heavy Win interact with matter, inelastic collision (leading to electronic energy loss-S-e) and elastic collision (leading to nuclear energy loss-S-n) take place. In the present study, the effect of energetic ion species on thermoluminescence (TL) of polycrystalline aluminum oxide (PAO) is reported. PAO pellets of 6 mm diameter are irradiated with energetic Au9+, Ni7+ and Si7+ ions for the fluence of 1 x 10(13) ions cm(-2). A single well resolved prominent TL glow with peak at 538 K is observed in Si7+ irradiated samples. However, in Ni7+ and Au9+ irradiated samples a prominent TL glow with peak at 610 K along with a shoulder at 513 K is observed. On the other hand, when PAO samples are irradiated with gamma-rays two well separated TL glows with peaks at 483 K and 638 K are observed. A prominent PL emission with peak at 430 nm besides a weak emission with peak at 480 nm and a shoulder at 525 nm are observed in 120 MeV Au9+ ion irradiated samples when excited with 320 nm. These PL peaks are attributed to F, F-2(+) and F-2(2+)-centers respectively. However, in Si7+ irradiated samples a single PL emission peak at 430 nm is observed and it is attributed to F-centers

Swift heavy ion irradiation induced phase transformation in calcite single crystals

Ion irradiation induced phase transformation in calcite single crystals have been studied by means of Raman and infrared spectroscopy using 120 MeV Au(9+) ions. The observed bands have been assigned according to group theory analysis. For higher fluence of 5 x 10(12) ion/cm(2), an extra peak on either side of the 713 cm(-1) peak and an increase in the intensity of 1085 cm(-1) peak were observed in Raman studies. FTIR spectra exhibit extra absorption bands at 674 1589 cm(-1) and enhancement in bands at 2340 and, 2374 cm(-1) was observed. This might be due to the phase transformation from calcite to vaterite. The damage cross section (sigma) for all the Raman and FTIR active modes was determined. The increase of FWHM, shift in peak positions and appearance of new peaks indicated that calcite phase is converted into vaterite. (C) 2009 Elsevier Ltd. All rights reserved

Swift heavy ion induced thermoluminescence studies in polycrystalline aluminum oxide

161-164 When energetic swift heavy ions interact with matter, inelastic collision (leading to electronic energy loss-Se) and elastic collision (leading to nuclear energy loss -Sn) take place. In the present study, the effect of energetic ion species on thermoluminescence (TL) of polycrystalline aluminum oxide (PAO) is reported. PAO pellets of 6 mm diameter are irradiated with energetic Au9+, Ni7+ and Si7+ ions for the fluence of 1×1013 ions cm-2. A single well resolved prominent TL glow with peak at 538 K is observed in Si7+ irradiated samples. However, in Ni7+ and Au9+ irradiated samples a prominent TL glow with peak at 610 K along with a shoulder at 513 K is observed. On the other hand, when PAO samples are irradiated with g-rays two well separated TL glows with peaks at 483 K and 638 K are observed. A prominent PL emission with peak at 430 nm besides a weak emission with peak at 480 nm and a shoulder at 525 nm are observed in 120 MeV Au9+ion irradiated samples when excited with 320 nm. These PL peaks are attributed to F, F2+ and F22+-centers respectively. However, in Si7+ irradiated samples a single PL emission peak at 430 nm is observed and it is attributed to F-centers. </smarttagtype

Determination of the chemical states of impurities in natural kyanite by the ionoluminescence technique

Ionoluminescence (IL) of natural kyanite crystals was studied during 120 MeV Au9+ ion irradiation in the fluence range 1.50-12 1011 ions/cm2. The IL spectrum exhibits sharp peaks at 689, 694, 705, 713 and 716 nm, along with a broad emission peak at 530 nm recorded for all samples investigated. The sharp emission peaks at 689 and 694 nm are attributed to R2 and R1 lines of Cr3+ impurities, and they are related to the transition 2Eg 4A2g. The peaks at 705-716 nm are attributed to Fe3+ impurities and are related to the transition 4T1g 6A1g. It was observed that up to a given fluence, the IL peak intensity grows, reaches a maximum and gradually decreases with increase of Au9+ ion fluence. The decrease in IL intensity might be attributed to disorder produced by dense electronic excitation under swift heavy ion irradiation. The stability of the chemical species was studied both with and without irradiation by means of FTIR spectroscopy. The results confirm that the Si-O-Al, Al-O and Si-O (23) type species are destroyed due to amorphization