title: Structural characterization, thermoluminescence studies and kinetic parameters of SrSO4:Eu nanophosphors under X-ray and gamma excitations.
abstract: Nanostructured SrSO4:Eu phosphors with high thermoluminescence (TL) emission temperatures have been synthesized through a controlled chemical precipitation method. Structural analysis and TL studies under both γ-ray and X-ray excitations were done. The phosphors were characterized using Powder X-ray diffraction, X-ray photoelectron spectroscopy, SEM, TEM, thermogravimetry, UV-VIS and photoluminescence studies. The average crystallite size estimated using PXRD data is found to be around 40nm. XPS and PL studies reveal that Eu(2+) ions are the luminescence emission centres in the phosphor. The phosphor is found to be highly TL sensitive to both γ-rays and X-rays with very high emission temperature which is not reported so far. The emission behaviour is suitable for environmental radiation dosimetry applications. The TL glow curve shows well-defined isolated high temperature emission peak at 312°C under 2Gy γ-excitation and 284°C for low energy diagnostic X-ray irradiation and 271°C for high energy therapeutic X-rays. Chen's peak shape method is applied to obtain the kinetic parameters behind the TL emission. The TL mechanism is found to follow second order kinetics, suggesting the probability of re-trapping of charge carriers.
authors.affiliation: Mahatma Gandhi College, Kesavadasapuram, Pattom Palace P.O., Thiruvananthapuram -695004, India. Electronic address: jsnair.india@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Jayasudha
authors.affiliation: Mahatma Gandhi College, Kesavadasapuram, Pattom Palace P.O., Thiruvananthapuram -695004, India.
authors.forename: K
authors.initials: K
authors.lastname: Madhukumar
authors.affiliation: Mahatma Gandhi College, Kesavadasapuram, Pattom Palace P.O., Thiruvananthapuram -695004, India.
authors.forename: C M K
authors.initials: CM
authors.lastname: Nair
authors.affiliation: Mahatma Gandhi College, Kesavadasapuram, Pattom Palace P.O., Thiruvananthapuram -695004, India.
authors.forename: Resmi G
authors.initials: RG
authors.lastname: Nair
authors.affiliation: Mahatma Gandhi College, Kesavadasapuram, Pattom Palace P.O., Thiruvananthapuram -695004, India.
authors.forename: V M
authors.initials: VM
authors.lastname: Anandakumar
authors.affiliation: State Institute of Cancer Research, Medical College P.O., Thiruvananthapuram -695011, India.
authors.forename: Thayal Singh
authors.initials: TS
authors.lastname: Elias
keywords: Photoluminescence; Radiation dosimetry; Thermoluminescence