Carbothermal reduction synthesis of alumina ceramics for luminescent dosimetry

Thermoluminescence (TL) curves of Al2O3–BeO ceramic samples synthesized during high‐temperature treatment of nanostructured Al2O3 compacts in vacuum with the presence of graphite in BeO crucibles are studied. Temperature ranges of certain TL peaks emission at the synthesis temperature varied from 1200 to 1400 °C are found. A comparative analysis of the TL peaks temperature position and the nature of traps in the obtained ceramics with single crystalline Al2O3, BeO, and BeAl2O4 analogs is carried out. Spectral composition of different TL peaks is investigated. It is found that oxygen vacancies and their aggregates play the main role in the TL emission centers formation in the samples under study. A complex structure of the dominating luminescence band at 4.0 eV in the dosimetric peak at 530 K of the ceramics synthesized at 1400 °C is found. This band is shown to be a superposition of three bands with the maxima at 3.11, 3.80, and 4.17 eV, resulted from F, F+ centers and presumably from Fcat‐type centers in aluminum oxide. The obtained results are essential to control and modify TL properties of Al2O3–BeO ceramics to create luminescence detectors of high‐dose radiation.

show abstract

“…[ 19 ] Successful cases of using the peak at 450 K in nanoceramics for high‐dose dosimetry (up to 1 kGy) of beta radiation are known. [ 19 ]…”

Section: Resultsmentioning

confidence: 99%

“…Such materials include, for example, LiF:Mg,Cu,P; BaSO 4 :Eu; CaSO 4 :Dy; Ba 0.97 Ca 0.03 SO 4 :Eu; α‐Al 2 O 3 , etc. [ 15–19 ]…”

Section: Introductionmentioning

confidence: 99%

Spectrally Resolved Thermoluminescence of Anion‐Deficient Al₂O₃–BeO Ceramics for High‐Dose Dosimetry

Nikiforov

Ananchenko

Borbolin

et al. 2020

Physica Status Solidi (a)

Self Cite

View full text Add to dashboard Cite

show abstract

“…В работах [24,25] нами было показано, что в спектрах оптического поглощения прозрачных микро-и нанокерамик, подвергнутых электронной бомбардировке, регистрируются полосы, характерные для F-и F + -центров. Микрокерамика получена методом одноосного горячего прессования в графитовой пресс-форме, что по всей видимости послужило причиной возникновения анион-ных вакансий по механизму термохимического окрашивания [26]. В результате последующего облучения 130 keV электронами происходит их локализация на анионных вакансиях.…”

Section: Discussionunclassified

Парамагнитные антисайт Mn-дефекты в нанокерамике алюмомагниевой шпинели

Зацепин¹,

Киряков²,

Байтимиров³

et al. 2020

Физика Твердого Тела

View full text Add to dashboard Cite

The influence of structural and dimensional factors on the formation of intrinsic and impurity paramagnetic centers in nanoceramics of aluminum-magnesium spinel is studied. The studied samples (with a grain size of 30 nm) were obtained by thermobaric synthesis. Microcrystalline ceramics and a MgAl2O4 single crystal were used as standards. The single crystal and microceramics contain characteristic Mn2+ paramagnetic centers (hyperfine structure constant (HFS) A = 82 G). In the studied nanoceramic samples in the initial state, both impurity Mn2+ and intrinsic F+ centers are detected. In contrast to nanoceramics, in reference samples centers of the F+ type appear only after irradiation with 130 keV by accelerated electrons. The parameters of the Mn2+ centers in nanoceramics differ significantly from those in microceramics and single crystals. For the Mn2+ center in nanoceramics, the EPR signal is characterized by two anomalous HFS constants (A1 = 91.21 G, A2 = 87.83 G) caused by two varieties of octahedrally coordinated manganese ions (anti-site defects [Mn2+]Al3+). The specific features of the spectral parameters of manganese centers correlate with a decrease in the lattice parameter of MgAl2O4 in the nanostructured state. The observed effects are interpreted based on the proposed charge compensation scheme of [Mn2+]Al3+ with an aluminum anti-site defect and an F+ center.

show abstract

“…Как было показано в предыдущих работах [26], для беспримесной керамики увеличение температуры отжига приводит к росту концентрации F-центров. Для керамики оксида алюминия с примесью магния наблюдается подобный эффект.…”

Section: результаты и обсуждениеunclassified

Тушение Люминесценции В Керамиках Оксида Алюминия Допированных Магнием

Звонарев¹,

Смирнов²

2019

Физика Твердого Тела

View full text Add to dashboard Cite

The effect of magnesium impurity on luminescent properties of alumina ceramics sintered at high temperatures under vacuum is studied by pulsed cathodoluminescence, photoluminescence, and thermoluminescence. At dopant concentrations >1 wt %, high-temperature synthesis results in formation of defects associated with magnesium, which were identified in the pulsed cathodoluminescence (520 nm) and photoluminescence (767 nm) spectra, as well as in the thermoluminescence curves (380 K). It is found that increased magnesium concentration leads to luminescence quenching of the intrinsic centers ( F centers) of alumina in the PCL emission band at 400 nm, impurity defects (Mn^4+ and Cr^3+) in the photoluminescence emission bands at 673 and 689 nm, and all the recorded thermoluminescence peaks at 380, 450, and 615 K.

show abstract

Carbothermal reduction synthesis of alumina ceramics for luminescent dosimetry

Cited by 33 publications

References 14 publications

Spectrally Resolved Thermoluminescence of Anion‐Deficient Al₂O₃–BeO Ceramics for High‐Dose Dosimetry

Spectrally Resolved Thermoluminescence of Anion‐Deficient Al₂O₃–BeO Ceramics for High‐Dose Dosimetry

Парамагнитные антисайт Mn-дефекты в нанокерамике алюмомагниевой шпинели

Тушение Люминесценции В Керамиках Оксида Алюминия Допированных Магнием

Contact Info

Product

Resources

About

Carbothermal reduction synthesis of alumina ceramics for luminescent dosimetry

Cited by 33 publications

References 14 publications

Spectrally Resolved Thermoluminescence of Anion‐Deficient Al2O3–BeO Ceramics for High‐Dose Dosimetry

Spectrally Resolved Thermoluminescence of Anion‐Deficient Al2O3–BeO Ceramics for High‐Dose Dosimetry

Парамагнитные антисайт Mn-дефекты в нанокерамике алюмомагниевой шпинели

Тушение Люминесценции В Керамиках Оксида Алюминия Допированных Магнием

Contact Info

Product

Resources

About

Spectrally Resolved Thermoluminescence of Anion‐Deficient Al₂O₃–BeO Ceramics for High‐Dose Dosimetry

Spectrally Resolved Thermoluminescence of Anion‐Deficient Al₂O₃–BeO Ceramics for High‐Dose Dosimetry