کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10731418 | 1043221 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
EPR and TSL studies on MgB4O7 doped with Tm: role of BO32â in TSL glow peak at 470Â K
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موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
تشعشع
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چکیده انگلیسی
Electron paramagnetic resonance (EPR), thermally stimulated luminescence (TSL), photoacoustic spectrometric (PAS) and fluorescence studies were conducted on gamma-irradiated MgB4O7: Tm phosphor. EPR spectra of irradiated samples revealed the formation of BO32-, a hole-trapped radical at room temperature. The principal values for the g and A tensors are gâ¥â2.0071, gâ¥=2.0131 and Aâ¥â14G, Aâ¥=7G, respectively. In addition to this, the radical without any hyperfine structure was identified as O2-(gâ¥=2.0385 and gâ¥=2.0023). TSL studies showed the presence of an intense glow peak around 470 K and a weak shoulder at 550 K. Temperature dependence studies of the EPR signals in the range 300-600 K showed the thermal destruction of BO32- radical around 470 K. The observed TSL emission is caused by the recombination of thermally released holes from BO32- radical with Tm2+ ion. The energy released in the electron-hole recombination process is used for the excitation of Tm3+ resulting in a prominent glow 470 K. TSL emission studies confirmed that Tm3+ acts as luminescent center for the prominent peak at 470 K. The trap depth for this peak has been determined to be 0.975±0.03eV from both TSL and EPR methods.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Radiation Measurements - Volume 40, Issue 1, September 2005, Pages 69-75
Journal: Radiation Measurements - Volume 40, Issue 1, September 2005, Pages 69-75
نویسندگان
N.K. Porwal, R.M. Kadam, T.K. Seshagiri, V. Natarajan, A.R. Dhobale, A.G. Page,