کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1496857 | 992976 | 2007 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Time resolved luminescence of quartz from Nigeria
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Characteristics of luminescence lifetimes and luminescence intensity obtained from time resolved spectra of quartz from Nigeria are presented. The luminescence was pulse-stimulated at 11 μs width at 470 nm. Samples used consisted of unannealed quartz as well as samples annealed at 500 °C, 600 °C, 700 °C, 800 °C and 900 °C. The luminescence lifetimes and luminescence intensities were studied as a function of annealing temperature, irradiation dose and measurement temperature. It was found that there is a decrease, although non-monotonic, in the luminescence lifetime with change in annealing temperature from 20 to 900 °C. In addition, lifetimes extracted from time resolved spectra of unannealed samples as well as ones annealed at 500 °C and 600 °C are initially independent of irradiation dose but do later decrease with further irradiation. Regarding the luminescence intensity it was observed that in general, the intensity passes through a peak as the measurement temperature is increased from 20 to 200 °C with slight differences in the detailed pattern dependent on preheating. Activation energies for thermal quenching and thermal assistance evaluated from temperature-dependent changes of luminescence lifetime and luminescence intensity are given. The results are discussed in terms of a model consisting of three luminescence centres with probability of hole trapping during irradiation being highest for the luminescence centre associated with the least lifetime.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Optical Materials - Volume 29, Issue 12, August 2007, Pages 1844-1851
Journal: Optical Materials - Volume 29, Issue 12, August 2007, Pages 1844-1851
نویسندگان
F.O. Ogundare, M.L. Chithambo,