Comprehensive kinetic analysis of thermoluminescence peaks of α-Al2O3:C,Mg
Comprehensive kinetic analysis of thermoluminescence peaks of α-Al2O3:C,Mg
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DOI：
10.1016/j.jlumin.2017.01.003
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发表时间：
2017-05-01
影响因子：
3.6
通讯作者：
Chithambo, M. L.
中科院分区：
文献类型：
--
作者：
Kalita, J. M.;Chithambo, M. L.
本文对α-Al_2 O_3：C，Mg中的发光峰进行了动力学分析。在β辐射至1戈伊后以1 ℃/s测量的热致发光辉光曲线显示出在161 ℃的高强度峰（下文称为主峰）和分别在42、72、193、279、330、370 ℃的六个较低强度的次峰。为便于参考，将次峰分别标记为I、II、IV、V、VI和VII，主峰标记为峰III。用初始上升、全峰、峰形、变升温速率和辉光曲线解卷积方法以及磷光法对发光峰进行了动力学分析。使用T-m-T-stop，T-m-dose和磷光分析，峰的动力学级已被评估为一级。用峰形法、全峰法和反卷积法进行分析，得到了相同的结论。峰I至VII的活化能计算为分别类似于0.83、0.96、1.37、1.20、1.15、1.61和1.94 eV。所有峰的频率因子为109至1014 s（-1）的量级。考虑了热猝灭对峰的影响。发现峰III、IV和V（在这方面可以方便地研究的唯一峰）受热淬灭的影响。计算峰III的热猝灭活化能为0.96 +/-0.03eV，峰VI为0.95 +/-0.07eV，峰V为1.26 +/-0.08eV。本文讨论了热猝灭现象.根据本工作的发现，建立了一个能带模型来讨论α-Al_2 O_3：C，Mg的发光机理。(C)2017 Elsevier B. V.版权所有。
A comprehensive kinetic analysis of the glow peaks in alpha-Al2O3:C,Mg is reported. A thermoluminescence glow curve measured at 1 degrees C/s after beta irradiation to 1 Gy shows a high intensity peak hereafter referred to as the main peak at 161 degrees C and six lower intensity secondary peaks at 42, 72, 193, 279, 330, 370 degrees C respectively. For ease of reference, the secondary peaks are labelled as I, II, IV, V, VI and VII respectively and the main peak denoted peak III. Kinetic analysis of the glow peaks has been carried out using the initial rise, whole glow peak, peak shape, variable heating rate and glow curve deconvolution methods as well as by way of phosphorescence. Using T-m-T-stop, T-m-dose and phosphorescence analyses, the order of kinetics of the peaks has been evaluated as first order. Analysis by the peak shape, whole glow peak and deconvolution methods produce the same conclusion. The activation energy of peaks I through VII are calculated as similar to 0.83, 0.96, 1.37, 1.20, 1.15, 1.61 and 1.94 eV respectively. The frequency factors for all the peaks are of the order of 109 to 1014 s(-1). The question of thermal quenching affecting the peaks was considered. The peaks III, IV and V, the only ones that could be conveniently studied in this regard, were found to be affected by thermal quenching. The activation energy for thermal quenching was calculated for peak III as 0.96 +/- 0.03 eV, for peak VI as 0.95 +/- 0.07 eV and for peak V as 1.26 +/- 0.08 eV. The thermal quenching phenomenon has been discussed with reference to and F+ centres. An energy band model has been developed to discuss the luminescence mechanisms in alpha-Al2O3:C,Mg in light of finding in this work. (C) 2017 Elsevier B.V. All rights reserved.