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Jeffries, B. J.; Brewer, J. D.; Summers, G.P.

doi:10.1103/physrevb.24.6074

Cited by 37 publications

(13 citation statements)

References 16 publications

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“…Видно, что в пределах пика наблюдается падение величины отношения интенсивно-стей ТЛ F-и F + -центров. Эта закономерность ранее уже наблюдалась в анион-дефектных кристаллах оксида алюминия, легированных магнием [15] и одновременно магнием и хромом [32]. Новым важным результатом настоящей работы является обнаружение этого эффек-та в номинально чистых дозиметрических кристаллах α-Al 2 O 3 , а также зависимости степени его проявления от формы основного ТЛ-пика.…”

Section: св никифоров вс кортовunclassified

“…Менее изучена природа высокотемпературных ловушек, ответственных за дозиметрический ТЛ-пик в анион-дефектном α-Al 2 O 3 . Предположение о возможной дырочной природе данных центров было высказано в работе [8] на основе обна-руженных различий спектрального состава ТЛ низко-и высокотемпературной части пика при 400−500 K в образцах корунда, легированного магнием [15]. Это предположение использовалось для объяснения разли-чий в форме кривых фототрансферной люминесценции, стимулированной одновременно оптическим и терми-ческим воздействием, в образцах с узким и двойным ТЛ-пиком [7].…”

Section: Introductionunclassified

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Роль дырочных ловушек в термолюминесценции дозиметрического пика в анион-дефектных монокристаллах alpha-Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-

Nikiforov¹,

Кортов²

2017

Физика Твердого Тела

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Исследованы термолюминесцентные свойства анион-дефектных монокристаллов оксида алюминия с различной полушириной основного (дозиметрического) пика при 400-500 K. Получены новые экспериментальные подтверждения дырочной природы ловушек, ответственных за высокотемпературную часть данного пика. Введение в рассмотрение дырочных центров захвата позволило теоретически обосновать экспериментально наблюдаемые зависимости интенсивности термолюминесценции (ТЛ), температурного положения и полуширины основного пика от степени заполнения глубоких ловушек. Дырочная природа ловушек высокотемпературной части основного ТЛ-пика подтверждается при анализе особенностей ТЛ мелких центров захвата, обусловливающих ТЛ при 350 K, а также при изучении температурных изменений спектра ТЛ основного пика. DOI: 10.21883/FTT.2017.09.44839.051

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Section: св никифоров вс кортовunclassified

Section: Introductionunclassified

Роль дырочных ловушек в термолюминесценции дозиметрического пика в анион-дефектных монокристаллах alpha-Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-

Nikiforov¹,

Кортов²

2017

Физика Твердого Тела

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confidence: 99%

“…The concentration of F + centers can be varied by exciting the studied crystals with UV light in the absorption band for F centers (210 nm). In this case, the conversion F center → F + center occurs and the free electrons generated occupy traps, including deep traps [7,8].The aim of this work was to analyze the kinetic parameters of thermoluminescence within the temperature range of the dosimetric peak for irradiated crystals of anion-deficient α-Al 2 O 3 , taking into account the noted characteristics.Samples and experimental procedure. Samples (diameter 5 mm and thickness 1 mm) of nominally pure anion-deficient single crystals of α-Al 2 O 3 were grown under strong reducing conditions [1].…”

mentioning

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Characteristic features of thermoluminescence kinetics in dosimetric aluminum oxide crystals

Кортов¹,

uulu²,

Vainshtein³

2006

J Appl Spectrosc

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We have studied the thermoluminescence curves in the 420 nm band (F centers) and the 330 nm band (F + centers) within the temperature range of the dosimetric peak (T max = 450 K) in anion-deficient aluminum oxide crystals. Assuming general-order kinetics, we have analyzed the thermoluminescence decay curves on the rising and falling sides of the dosimetric peak, in samples with different degrees of deep trap filling. We have established differences in the order of the kinetics within different temperature ranges of the dosimetric peak.Introduction. The thermoluminescence and kinetic properties of anion-deficient aluminum oxide single crystals have been studied in connection with their application for ionizing radiation dosimetry [1][2][3][4]. However, so far there has been insufficient study of the nature of the active centers and the mechanism for thermoluminescence (TL) at the dosimetric peak at 450 K. We know [1, 2, 5] that within this peak we observe mainly luminescence of F centers (oxygen vacancies with two trapped electrons) and also a number of thermoluminescence features: a dependence of the intensity of luminescence for the F centers (420 nm) on the heating rate, a decrease in the average activation energy, superlinearity of the dose curve. Establishment of the role played in the indicated processes by deep trapping centers, the thermal ionization of which occurs at 730 K and 880 K, represents important progress. Deep trap filling is connected with the above-indicated characteristics, since it determines the competition for capture of charge carriers in the trap, which are responsible for the dosimetric peak. Data are available [6] indicating that this peak is not an elemental peak and that different luminescence mechanisms can be realized within its temperature range.We also know [2] that in the TL spectrum of the dosimetric peak there is a 330 nm component due to luminescence of F + centers (oxygen vacancies with one trapped electron). The concentration of F + centers can be varied by exciting the studied crystals with UV light in the absorption band for F centers (210 nm). In this case, the conversion F center → F + center occurs and the free electrons generated occupy traps, including deep traps [7,8].The aim of this work was to analyze the kinetic parameters of thermoluminescence within the temperature range of the dosimetric peak for irradiated crystals of anion-deficient α-Al 2 O 3 , taking into account the noted characteristics.Samples and experimental procedure. Samples (diameter 5 mm and thickness 1 mm) of nominally pure anion-deficient single crystals of α-Al 2 O 3 were grown under strong reducing conditions [1]. For the irradiation, we used a β radiation source based on the 90 Sr/ 90 Y isotopes, providing a test dose of 64 mGy at the sample location for 2 min.The TL curves were recorded using an MUM grating monochromator and an FÉU-39A photomultiplier. The monochromator was used to isolate the luminescence bands of the F and F + centers. The original samples were preannealed up to a tempera...

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“…Much work [6][7][8][9] has been done to study the TL properties of Al 2 O 3 crystals in the range 90-500 K. These studies have shown that TL peaks at 60, 100, 220, 260, and 290 K were associated with F-type centers and 435 K peak was attributed to V-type centers. Little work has been done though on the TL properties of Al 2 O 3 crystals grown in a reducing atmosphere.…”

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Thermoluminescence of Al2O3 crystals grown by temperature gradient techniques

et al. 2013

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Color center concentrations of the Al 2 O 3 crystal grown by temperature gradient techniques were calculated from Gaussian fits to absorption spectra. The concentrations for F-and F + -centers at 204, 232, and 255 nm were determined to be 1.361×10 17 , 0.098×10 17 , and 0.325×10 17 cm −3 , respectively. Studies have shown that the thermoluminescence (TL) glow curve exhibits a prominent 450 K peak that matches well the first-order fitting curve. The thermal activation energy E and frequency factor s of the trap were determined to be 0.94456±0.00545 eV and 5.8703×10 11 s −1 . With this theoretical analysis, a simple one-trap/one-center TL model is presented to provide a theoretical explanation of the TL process. In this paper we present calculations of the color-center concentrations of the Al 2 O 3 crystals grown under a reducing atmosphere by temperature gradient techniques (TGTs). The TL glow curve, which was different from that of previous reports, was also analyzed by first-order kinetic curve fitting. Based on the fitted parameters, a simple model was developed to enable a theoretical analysis of experimental TL data.

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Photoconductivity and charge trapping inα−Al2O3

Cited by 37 publications

References 16 publications

Роль дырочных ловушек в термолюминесценции дозиметрического пика в анион-дефектных монокристаллах alpha-Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-

Роль дырочных ловушек в термолюминесценции дозиметрического пика в анион-дефектных монокристаллах alpha-Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-

Characteristic features of thermoluminescence kinetics in dosimetric aluminum oxide crystals

Thermoluminescence of Al2O3 crystals grown by temperature gradient techniques

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