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Gupta SK, Modak B, Tyagi M, Rawat NS, Modak P, Sudarshan K. Harvesting Light from BaHfO 3/Eu 3+ through Ultraviolet, X-ray, and Heat Stimulation: An Optically Multifunctional Perovskite. ACS Omega 2022; 7:5311-5323. [PMID: 35187346 PMCID: PMC8851442 DOI: 10.1021/acsomega.1c06474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 01/21/2022] [Indexed: 05/09/2023]
Abstract
Materials with optical multifunctionality such as photoluminescence (PL), radioluminescence, and thermoluminescence (TL) are a boon for a sustainable society. BaHfO3 (barium hafnium oxide [BHO]) under UV irradiation demonstrated visible PL endowed by oxygen vacancies (OVs). Eu3+ doping in BHO (BHOE) introduces f-state impurity levels just below the conduction band for both Eu@Ba and Eu@Hf sites, causing efficient host-to-dopant energy transfer, generating intense 5D0 → 7F1 magnetic dipole transitions (MDT) with internal quantum yield of ∼70%. X-ray photoelectron spectroscopy and electron paramagnetic resonance showed the formation of OVs in both BHO and BHOE samples with more vacancies in the doped sample. The positron lifetime measurements suggested that Eu3+ ions are distributed at both Ba2+ and Hf4+ sites. The association of OVs with Hf4+ and Eu3+ ions due to high charge/radius ratio is considered to be responsible for lowering the symmetry around Eu3+ ions to C 4v in BHOE. Density functional theory studies of defect formation energy justified the same. Time-resolved emission spectroscopy showed distinct spectra for Eu@Ba and Eu@Hf sites corresponding to symmetric and asymmetric environments, respectively. This could be highly relevant in designing color tunable phosphor by forcing dopant ions at one specific site because Eu@Ba displayed orange emission whereas Eu@Hf displayed red emission. We could further harness BHOE for X-ray scintillator application by designing a thin film, which showed efficient conversion of high-energy X-ray into visible light. Under beta irradiation; both BHO and BHOE showed distinct TL glow curves as shallow traps were formed in the former and deep traps in the latter, which could have long-term implications in harnessing this material for persistent luminescence. We believe that BHO/BHOE demonstrated an extraordinary credential as a perovskite for multifunctional applications in the area of defect-induced light emission, UV phosphor, X-ray scintillator, and TL crystals.
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Affiliation(s)
- Santosh Kumar Gupta
- Radiochemistry
Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha
National Institute, Anushaktinagar, Mumbai 400094, India
- , . Phone.: +91-22-25590636
| | - Brindaban Modak
- Chemistry
Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha
National Institute, Anushaktinagar, Mumbai 400094, India
| | - Mohit Tyagi
- Technical
Physics Division, Bhabha Atomic Research
Centre, Mumbai 400085, India
- Homi Bhabha
National Institute, Anushaktinagar, Mumbai 400094, India
| | - Narender Singh Rawat
- Radiological
Physics and Advisory Division, Bhabha Atomic
Research Centre, Mumbai 400085, India
- Homi Bhabha
National Institute, Anushaktinagar, Mumbai 400094, India
| | - Pampa Modak
- Radiological
Safety Division, Atomic Energy Regulatory
Board, Anushaktinagar, Mumbai 400094, India
- Homi Bhabha
National Institute, Anushaktinagar, Mumbai 400094, India
| | - Kathi Sudarshan
- Radiochemistry
Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha
National Institute, Anushaktinagar, Mumbai 400094, India
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Mandlik NT, Sahare PD, Kulkarni MS, Rawat NS, Gaikwad NP, Dhole SD. Study of optically stimulated luminescence and calculation of trapping parameters of K 2Ca 2(SO 4) 3:Eu nanophosphor. Appl Radiat Isot 2020; 167:109388. [PMID: 33011514 DOI: 10.1016/j.apradiso.2020.109388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 08/14/2020] [Accepted: 08/17/2020] [Indexed: 12/01/2022]
Abstract
K2Ca2(SO4)3:Eu nanophosphor was synthesized by chemical coprecipitation method and annealed at different temperatures from 400 to 900 °C. The nanophosphor annealed at 600 °C showed cubic structure with crystallite size ~25 nm. TEM shows morphology of K2Ca2(SO4)3:Eu nanophosphor was in the form of nanorods having diameter ~20 nm and length of ~100-200 nm. These samples were irradiated with gamma radiation for the doses varying from 10 mGy to 10 kGy and their Thermoluminescence (TL) and continuous-wave optically stimulated luminescence (CW-OSL) have been studied. CW-OSL response was found to be maximal for the sample annealed at 600 °C. The TL glow curve of the nanophosphor apparently showed a major peak at around 160 °C accompanied by three low intensity peaks at ~75, 215 and 285 °C. The traps responsible for all the TL peaks in K2Ca2(SO4)3:Eu were also found to be OSL sensitive. The qualitative correlation between TL peaks and CW-OSL response suggested that the traps associated with low temperature peaks are responsible for fast decay and the traps associated with the higher temperature peaks are responsible for slow decay of the OSL signal. OSL response showed linear behavior up to 1 kGy and saturated with further increase in the gamma dose. The wide OSL response makes studied K2Ca2(SO4)3:Eu nanophosphor a good candidate for high dose measurement.
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Affiliation(s)
- Nandkumar T Mandlik
- Department of Physics, Fergusson College, Savitribai Phule Pune University, Pune, 411004, Maharashtra, India.
| | - P D Sahare
- Department of Physics and Astrophysics, University of Delhi, Delhi, 110007, India.
| | - M S Kulkarni
- Health Physics Division, BARC, Mumbai, 400085, Maharashtra, India
| | - N S Rawat
- Radiological Physics and Advisory Division, BARC, Mumbai, 400 085, Maharashtra, India
| | - N P Gaikwad
- Radiological Physics and Advisory Division, BARC, Mumbai, 400 085, Maharashtra, India
| | - S D Dhole
- Department of Physics, Savitribai Phule Pune University, Pune, 411007, Maharashtra, India
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Kumar P, Sharma SD, Dhabekar B, Mishra DR, Rawat NS, Kadam S, Chaudhari S, Chandola RM, Agrawal S. PATIENT-SPECIFIC DOSIMETRY USING IN-HOUSE DEVELOPED OSL DISC DOSEMETERS. Radiat Prot Dosimetry 2020; 189:127-135. [PMID: 32140728 DOI: 10.1093/rpd/ncaa023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 06/10/2023]
Abstract
Circular discs of diameter 5 mm were made from three indigenously developed optically stimulated luminescent (OSL) phosphors for medical dosimetry. Dosimetric characteristics of these discs were evaluated for their use in machine and patient-specific dosimetry in radiotherapy. Uncertainty in dosimetric measurements using these discs was also estimated, and combined standard uncertainty in measurement of absorbed dose was found to be 3.34%. Characterisation studies indicate that OSL discs are suitable for dosimetric application in radiotherapy. These discs were also used for patient-specific dosimetry in conventional and conformal radiotherapy treatments (five different cases) vis-à-vis ionisation chamber and Gafchromic EBT3 film. Doses measured by OSL discs were found comparable to ionisation chamber and Gafchromic EBT3 film measured values and radiotherapy treatment planning system (TPS) calculated dose values in all the cases. The variation between TPS calculated dose values and OSL discs measured dose values was found within the measurement uncertainty.
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Affiliation(s)
- Pradip Kumar
- National Institute of Technology, Raipur, Chhattisgarh, India
- Atomic Energy Regulatory Board, Mumbai, Maharashtra, India
| | - Sunil Dutt Sharma
- Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
- Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Bhushan Dhabekar
- Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
- Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Devesh Ramdhar Mishra
- Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
- Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Narender Singh Rawat
- Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
- Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Sonal Kadam
- Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
| | | | | | - Sadhana Agrawal
- National Institute of Technology, Raipur, Chhattisgarh, India
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Kumar P, Dhabekar B, Sharma SD, Mishra DR, Rawat NS, Kadam S, Chaudhari S, Chandola RM, Agrawal S. Relative energy response of indigenously developed optically stimulated luminescence dosimeters Al 2 O 3 :C, LiMgPO 4 :B and LiCaAlF 6 :Eu,Y in therapeutic photon and electron beams. LUMINESCENCE 2020; 35:1217-1222. [PMID: 32515166 DOI: 10.1002/bio.3832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 03/25/2020] [Accepted: 05/07/2020] [Indexed: 11/07/2022]
Abstract
The relative energy responses of three indigenously developed optically stimulated luminescence (OSL) phosphors in the disc form were studied in therapeutic photon and electron beams. Calibration in terms of absorbed dose was carried out in the dose range 5-500 cGy in 60 Co gamma rays, high energy X-rays, and electron beams used in radiotherapy. The combined standard uncertainty in the estimation of absorbed dose using these OSL discs (OSLDs) was 3.3%. Dose-response curves of these OSLDs in 60 Co gamma rays, 6 and 10 MV (flat and unflat), 15 MV and 6 and 15 MeV electron beams were found to be linear. Furthermore, these OSLDs exhibited a relative energy-dependent response for both photon and electron beams. The relative energy response correction factor for photon and electron beams were in the range 1.01-1.05 and 1.03-1.06, respectively.
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Affiliation(s)
- Pradip Kumar
- National Institute of Technology, Raipur, India.,Atomic Energy Regulatory Board, Mumbai, India
| | - Bhushan Dhabekar
- Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
| | - Sunil Dutt Sharma
- Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
| | - Devesh Ramdhar Mishra
- Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
| | | | - Sonal Kadam
- Bhabha Atomic Research Centre, Mumbai, India
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Kumar P, Dutt Sharma S, Chandola RM, Mishra DR, Dhabekar B, Rawat NS, Kadam S, Agrawal S. Radiation dose measurements in a dental orthopantogram unit using indigenously developed optically stimulated luminescence dosimeters. LUMINESCENCE 2019; 34:444-449. [PMID: 31025441 DOI: 10.1002/bio.3637] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/13/2019] [Accepted: 03/29/2019] [Indexed: 11/11/2022]
Abstract
Dental orthopantogram (OPG)/cone beam computed tomography (CBCT) scanners are gaining popularity due to their 3D imaging with multiplanar view that provides clinical benefits over conventional dental radiography systems. Dental OPG/CBCT provides optimal visualization of adjacent overlaying anatomical structures that will be superpositioned in any single projection. The characteristics of indigenously developed optically stimulated luminescence dosimeters, namely, aluminium oxide doped with carbon (Al2 O3 :C), lithium magnesium phosphate doped with terbium and boron (LiMgPO4 :Tb,B) and lithium calcium aluminium fluoride doped with europium and yttrium (LiCaAlF6 :Eu,Y) were evaluated for their use in dental dosimetry. The dose-response of these dosimeters was studied at X-ray energies 60 kV, 70 kV and 81 kV. Radiation doses were also measured using Gafchromic film for comparison. Radiation dose was measured at eight different locations of a polymethyl methacrylate (PMMA) head phantom including eyes. The optically stimulated luminescence (OSL) sensitivity of LiMgPO4 :Tb,B is about 1.5 times and LiCaAlF6 :Eu, is about 20 times higher than the sensitivity of Al2 O3 :C. It was found that measured radiation doses by the three optically stimulated luminescence dosimeters (OSLDs) and Gafchromic film in the occipital region (back side) of a PMMA phantom, were consistent but variations in dose at other locations were significantly higher. The three OSLDs used in this study were found to be suitable for radiation dose measurement in dental units.
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Affiliation(s)
- Pradip Kumar
- National Institute of Technology, Raipur, India.,Atomic Energy Regulatory Board, Mumbai, India
| | | | | | | | | | | | - Sonal Kadam
- Bhabha Atomic Research Centre, Mumbai, India
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Mishra DR, Soni A, Rawat NS, Bokam G. Study of thermoluminescence (TL) and optically stimulated luminescence (OSL) from α-keratin protein found in human hairs and nails: potential use in radiation dosimetry. Radiat Environ Biophys 2016; 55:255-264. [PMID: 26846648 DOI: 10.1007/s00411-016-0634-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 01/16/2016] [Indexed: 06/05/2023]
Abstract
The thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of human nails and hairs containing α-keratin proteins have been investigated. For the present studies, black hairs and finger nails were selectively collected from individuals with ages between 25 and 35 years. The collected hairs/nails were cut to a size of < 1 mm and cleaned with distilled water to remove dirt and other potential physical sources of contamination. All samples were optically beached with 470 nm of LED light at 60 mW/cm(2) intensity and irradiated by a (60)Co γ source. The hair and nail samples showed overlapping multiple TL glow peaks in the temperature range from 70 to 210 ° C. Continuous wave (CW)-OSL measurements of hair samples at a wavelength of 470 nm showed the presence of two distinct OSL components with photoionization cross section (PIC) values of about 1.65 × 10(-18) cm(2) and about 3.48 × 10(-19) cm(2), while measurements of nail samples showed PIC values of about 6.98 × 10(-18) cm(2) and about 8.7 × 10(-19) cm(2), respectively. This difference in PIC values for hair and nail samples from the same individual is attributed to different arrangement of α-keratin protein concentrations in the samples. The OSL sensitivity was found to vary ± 5 times among nail and hair samples from different individuals, with significant fading (60% in 11 h) at room temperature. The remaining signal (after fading) can be useful for dose estimation when a highly sensitive OSL reader is used. In the absorbed dose range of 100 mGy-100 Gy, both the TL and OSL signals of hair and nail samples showed linear dose dependence. The results obtained in the present study suggest that OSL using hair and nail samples may provide a supplementary method of dose estimation in radiological and nuclear emergencies.
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Affiliation(s)
- D R Mishra
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400 085, India.
| | - A Soni
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400 085, India
| | - N S Rawat
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400 085, India
| | - G Bokam
- Radiological Safety Division, Atomic Energy Regulatory Board, Mumbai, 400 094, India
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Rawat NS, Negi A, Thukral BB, Saxena NC. CT of diffuse fatty infiltration of renal parenchyma secondary to bilateral giant angiomyolipomas- a case report. Indian J Radiol Imaging 2006. [DOI: 10.4103/0971-3026.29019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- N S Rawat
- Department of Radiodiagnosis & Imaging, Vardhman Mahavir Medical College & Safdarjung Hospital, New Delhi, India
| | - A Negi
- Department of Radiodiagnosis & Imaging, Vardhman Mahavir Medical College & Safdarjung Hospital, New Delhi, India
| | - B B Thukral
- Department of Radiodiagnosis & Imaging, Vardhman Mahavir Medical College & Safdarjung Hospital, New Delhi, India
| | - N C Saxena
- Department of Radiodiagnosis & Imaging, Vardhman Mahavir Medical College & Safdarjung Hospital, New Delhi, India
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Rawat NS, Negi A, Sangwan S, Sharma U, Thukral BB, Saxena NC. Aggressive adenocarcinoma of gallbladder with distant metastases and venous thrombosis at initial presentation. Indian J Radiol Imaging 2006. [DOI: 10.4103/0971-3026.32255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Abstract
The respirable coal dust samples were collected from the mine atmosphere during drilling of coal seams using 'Hexlet' apparatus. Sixteen dust samples were collected from each three different seams for investigations. After destruction of the organic matter by wet oxidation and filtering off the clay and silica, Fe, Ca, Mg, Na, K, Mn, Zn, Cu, Cd and Ni were determined directly in the resulting solution by atomic absorption spectrophotometric methods. The x-ray diffraction studies have shown the presence of kaolinite, quartz, pirrsonite, and beidellite clay minerals in the coal dust. The mass-size distribution of the coal dust has been studied by using micron photosizer. The results showed that the distribution are unimodal, asymmetric, and positively skew. Although the assumption of log-normality was useful in interpreting the results, closer observations indicated that the relationship between the size and weight of the particles can be represented by a second degree parabolic equation w = a + bS + cs2, where W and S are weight and size of the particles and a, b and c are constants. This equation helps us to characterise the mass of the respirable particles if the size is known. The studies throw light on the nature and mode of trace elements found in Indian Coal as well as on the causes of respiratory disease, pneumoconmiosis, affecting the workers in the mine environmental condition.
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Rawat NS, Sinha JK, Sahoo B. Atomic absorption spectrophotometric and X-ray studies of respirable dusts in Indian coal mines. Arch Environ Health 1982; 37:32-5. [PMID: 7059229 DOI: 10.1080/00039896.1982.10667529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Quantitative determination of 10 minor and 8 trace elements in respirable coal dust by atomic absorption spectrophotometry is described herein. The coal dust samples were collected in the mine atmosphere during drilling in coal seams. A "Hexhlet" apparatus specially designed and fitted with a horizontal elutriator was used to collect the respirable coal dust fraction. After destruction of organic matter by wet oxidation and filtering off the clay and silica, iron, calcium, magnesium, sodium, potassium, manganese, zinc, copper, cadmium, and nickel were determined directly in the resulting solution by atomic absorption spectrophotometry. The studies relate to the respiratory disease-pneumoconiosis-affecting coal mine workers. X-Ray diffraction studies have shown the presence of kaolin, quartz, pirrsonite and beidellite clay minerals in the coal dust.
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