Thermal stability of radiation-induced optical centers in non-stoichiometric spinel crystals

Gritsyna, V.T.; Kazarinov, Yu.G.

doi:10.1016/j.nimb.2006.04.136

Cited by 9 publications

(5 citation statements)

References 15 publications

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“…These results suggest that PL from 3.0 at% Mn doped MgAl 2 O 4 is sensitive to the temperature variation from 30 to 200 • C. Concentration quenching, thermal quenching and crystal field strength may influence on PL properties of Mn doped MgAl 2 O 4 . Crystal field effects on the optical properties of spinel crystal have also been reported in non-stoichiometric Cr doped spinel crystals by C. Garapon, 13 A. Kamińska14 and V. T. Gritsyna 15. PL lifetime of Mn doped MgAl 2 O 4 is also measured using pulse YAG laser (λ = 355 nm) excitation.…”

mentioning

confidence: 56%

Temperature Variation of Photoluminescence from Mn Doped Spinel Crystals for a Fluorescence Thermometer Application

Sakuma

Minowa

Katsumata

et al. 2014

ECS Solid State Letters

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Temperature variations of Photoluminescence (PL) spectra have been evaluated from Mn doped spinel with various Mn concentrations from 1.0 to 5.0 at% for a fluorescence thermometer application. PL peaking at around 520 nm, which varies with Mn concentration, decreases linearly with temperature from 30 to 200 • C. PL intensities, peak wavelength, temperature coefficient and thermal activation energy also vary with Mn concentration. Concentration quenching and variation of crystal field strength is thought to affect on PL intensity, peak wavelength, temperature coefficient and thermal activation energy in Mn doped MgAl 2 O 4 crystals.Fluorescence thermometry is potentially useful for the temperature measurement under the extraordinary environments. 1 Various fluorescence thermo-sensors are, therefore, studied for the temperature measurement. 1-6 The performance of a fluorescence thermometer depends greatly on temperature variation of PL properties of thermosensor. PL properties of sensor materials are, therefore, important for fluorescence thermometer. [1][2][3][4][5][6] Spinel (MgAl 2 O 4 ) is stable against high temperature (melting point at 2130 • C) and large mechanical stress (the Mohs hardness is 8). Spinel crystal doped with Ti, Cr or Mn emits blue, red or green colored PL, respectively. 7-9 Thermo-sensor application of spinel has been reported on Cr doped MgAl 2 O 4 because of strong PL intensity, long PL lifetime and large temperature coefficient. 3 Mn doped spinel is also thought to be a useful thermo-sensor because of strong green colored PL excited by UV Light emitting diode (LED). From the investigations on PL 7-9 and cathode luminescence (CL) 10,11 in MgAl 2 O 4 , ZnAl 2 O 4 and Ba 2 B 5 O 9 Cl crystals, Mn 2+ ions in tetrahedral coordination have been reported to emit bright visible light luminescence at around 520 and 575 nm.In this paper, spinel crystals with various Mn concentrations are evaluated for fluorescence thermometer applications. Effects of Mn concentration on PL intensity, PL wavelength, temperature coefficient and thermal activation energy are reported and discussed based on the temperature dependences of PL properties. ExperimentalMn doped spinel (MgAl 2 O 4 ) crystals were prepared from highly pure 99.99 wt% (4N) Al 2 O 3 , (4N) MgO and 99.9 wt% (3N) Mn 2 O 3 . Powders were weighted and mixed with nominal composition, (Mn x , Mg 1−x )Al 2 O 4 , from x = 0.01 to 0.05 (from 1.0 to 5.0 at%) and sintered at 1150 • C for 3 h in air. Crystals were grown in pure (100 vol%) Ar atmosphere using a floating zone (FZ) technique (Crystal Systems Co., Japan). Mn doped spinel crystals typically with 5 mm diameter and 20 mm long were grown using FZ technique.X-ray powder diffraction patterns were evaluated using RINTUltima X-ray diffractmeter (Rigaku Co., Japan) with CuKα. Diffraction angle was calibrated by standard Si specimen. Excitation spectra and peak intensities of PL from grown crystals were measured by FP-6200 type fluorescence spectrometer (JASCO Co., Japan). PL spectra from grown crystals ...

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mentioning

confidence: 56%

Temperature Variation of Photoluminescence from Mn Doped Spinel Crystals for a Fluorescence Thermometer Application

Sakuma

Minowa

Katsumata

et al. 2014

ECS Solid State Letters

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“…Finally the Half-Value Layers (HVLs) which mean the minimum material thickness to reduce initial radiation intensity to its half, of the samples were calculated by using the following formula; (3) HVLs of the materials for Cs-137 gamma radioisotope source were listed in Table 4. As seen in Table 4, HVL for the SAT0 is the smallest value for Cs-137 gamma radiation whereas the SAT10 has the largest HVL.…”

Section: Resultsmentioning

confidence: 99%

“…MgAl 2 O 4 ) is a ceramic material with rather high radiation resistance, at least from the point of view of maintaining its mechanical and elastic properties [2]. One of the most important facilities of spinel is that it has excellent radiation resistance to neutron irradiation and use in nuclear fusion reactors as isolating material so it can be use for first-wall protection or as structural material where low nuclear activation and good high-temperature performance are required [3,4]. Since magnesium aluminum spinel is highly resistant to neutron irradiation it is considered to be a candidate material for fusion reactor application such as dielectric windows for radiofrequency heating system and insulators for magnetic coils [5].…”

Section: Introductionmentioning

confidence: 99%

An investigation of aluminum titanate-spinel composites behavior in radiation

Cevikbas¹,

Tuğrul²,

Onen³

et al. 2015

AIP Conference Proceedings

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Abstract.In the present work, the radiation attenuation properties of Aluminum titanate (Al 2 TiO 5 )-Spinel (MgAl 2 O 4 ) ceramics composites were investigated. Al 2 TiO 5 -MgAl 2 O 4 ceramics composites which have different Al 2 TiO 5 percentages (0%, 5% and 10%) were produced and performed against gamma sources. Cs-137 and Co-60 were used as gamma radiation sources. Transmission technique was used in the experiments. The linear and mass attenuation coefficients of the samples were carried out for gamma radiation sources. The experimental results were compared with the theoretical mass attenuation coefficients which were calculated by using XCOM computer code. Increasing Al 2 TiO 5 percentage in the Aluminum titanate/ Spinel ceramics composites causes the higher linear and mass attenuation coefficients of the composites against Cs-137 and Co-60 gamma radioisotopes. Therefore Also theoretical mass attenuation coefficients are compatible with the experimental results. In conclusion, increasing the Aluminum titanate ratio in the Al 2 TiO 5 -MgAl 2 O 4 ceramics composites increases the gamma shielding property of the Al 2 TiO 5 -MgAl 2 O 4 ceramics for nuclear shielding applications.

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“…Many studies have already been conducted on optical, dielectric and mechanical properties of irradiated MgAl 2 O 4 [13][14][15][16][17][18][19][20][21]. In our previous study, we observed the vibronic photoexcitation spectra in both neutron-and electronirradiated spinel [22].…”

Section: Introductionmentioning

confidence: 87%

Laser excited novel near-infrared photoluminescence bands in fast neutron-irradiated MgO·nAl2O3

Rahman

Haseeb

et al. 2016

Radiation Physics and Chemistry

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New near-infrared photoluminescence bands were observed in neutron-irradiated spinel single crystal upon excitation by a 532 nm laser. The surface morphology of the unirradiated and fast neutron-irradiated samples was investigated using atomic force microscopy and scanning probe microscopy. Fast neutronirradiated samples show a strong emission peak at 1,685 nm along with weak bands at 1,065 and 2,365 nm. The temperature dependence of the photoluminescence intensity was also measured. At lower temperatures, the dominant peak at 1,685 nm shifts toward lower energy whereas the other peaks remain fixed. Activation energies of luminescence quenching were estimated to be 5.7 and 54.6 meV for the lower and higher temperature regions respectively.

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Thermal stability of radiation-induced optical centers in non-stoichiometric spinel crystals

Cited by 9 publications

References 15 publications

Temperature Variation of Photoluminescence from Mn Doped Spinel Crystals for a Fluorescence Thermometer Application

Temperature Variation of Photoluminescence from Mn Doped Spinel Crystals for a Fluorescence Thermometer Application

An investigation of aluminum titanate-spinel composites behavior in radiation

Laser excited novel near-infrared photoluminescence bands in fast neutron-irradiated MgO·nAl2O3

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