Abstract
Optical absorption as well as thermoluminescence emission of LiF:Mg2+ single crystals have been measured before and after exposed to gamma radiation from Co-60 source. Result of DFT calculations for pure bulk LiF indicates a large reduction in band gap energy of the crystal after doping with Mg2+ ions. As impurity concentration of Mg2+ ions in LiF is increased, the activation energy of 225 and 313 nm trap centers increases linearly with almost same slope. However, the activation energy of trap centers absorbing at 250 nm remains nearly unchanged as doping concentration increased, indicating that these trap sites are independent of Mg2+ ions. Values of average experimental activation energy (E exp) for trap centers absorbing at 250, 225 and 313 nm for temperature range of 300–573 K have been obtained as 0.33 ± 0.030, 0.21 ± 0.012 and 0.16 ± 0.013 eV, respectively.
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References
H Zamai Thermal and Optical Characteristics of Defect Centers in Irradiated TLD-100 Dosimeters (Kansas State University USA) (1991)
P Klocek Handbook of Infrared Optical Materials (New York: Marcel Dekker) p 291 (1991)
H V Thai, QH N Thi and L N Ngoc VNU J. Sci. Math. Phys. 25 83 (2009)
M Puchalska, P Bilskiand and P Olko Rad. Meas. 42 601 (2007)
A F McKinlay Thermo-luminescence Dosimetry (Norwich: Adam Hilger. Ltd.) p 15 (1981)
R Nink and H J Kos J.Phys. C7 C127 (1976)
H Sadeghi, M R Jalali, S Mohammadi and M Kavosh Tehrani J. Basic. Appl. Sci. Res. 3 806 (2013)
C Junmeng, L Ronghou and F Shen Solid State Sci. 10 226 (2008)
M Karmakar, B Sarkar, S k Azharuddin, P S Mazumder, S D Singh, W S Singh and M Bhattacharya Indian J. Phys. 84 529 (2010)
O Kayacan, N Can,Y Karabulut and O Afsar Physica A 345 107 (2005)
C Furett Handbook of Thermoluminescence (Singapore: World Scientific) (2003)
G Baldacchini, P Chiacchiaretta, V Gupta, V Kalin and A P Voitovich Phys. Solid State 50 1747 (2008)
S J Singh, M Karmakar, M Bhattacharya and S D Singh Indian J. Phys. 86 113 (2012)
M Kumar, G Chourasiya, R K Kher, B C Bhatt and C M Sunta Indian J. Phys. 85 527 (2011)
K Tang, H Cui, H Zhu and Q Fan Rad. Meas. 41 24 (2007)
S Basun, G F Imbusch, D D Jia and W M Yen J. Lumin. 104 283 (2003)
M S Rasheedy Physica B: Phys. Condens. Matt. 228 342 (1996)
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Authors like to thank Payame Noor University for their financial support of the project.
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Sadeghi, H., Jalali, M.R., Mohammadi, S. et al. Effects of doping concentration on thermal activation energy of trap centers in irradiated LiF:Mg2+ single crystals. Indian J Phys 88, 375–379 (2014). https://doi.org/10.1007/s12648-013-0420-3
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DOI: https://doi.org/10.1007/s12648-013-0420-3
Keywords
- Thermo-luminescence
- Trap centers
- Charge carriers
- Impurity concentration
- Defect sites
- Absorption spectra
- Dosimeters
- DFT calculations