title: Low temperature synthesis, structural and dosimetric characterization of ZnAl2O4:Ce3+ nanophosphor.
abstract: Dosimetric properties of γ-irradiated ZnAl2O4:Ce(3+) (1-9 mol%) nanophosphors were studied and reported for the first time. The phosphor prepared by solution combustion route was well characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. PXRD patterns of calcined phosphor show pure cubic phase of ZnAl2O4:Ce(3+). Flake type morphology was observed from SEM studies. The particle size estimated by Scherrer's and Williamson Hall (W-H) plots and found to be in the range 11-17 nm. From photoluminescence (PL) studies two characteristic emission peaks at 363 and 480 nm were observed due to 5d-4f transitions of Ce(3+) ions. The thermoluminescence (TL) glow curves of ZnAl2O4:Ce(3+) (1-9 mol%) nanophosphor recorded two glow peaks 145 and 215 °C at a warming rate of 2.5 °C s(-1). The optimized TL intensity was observed for ∼5 mol% Ce(3+) concentration. The two TL glow peaks in the γ-irradiated (0.1-6 kGy) ZnAl2O4:Ce(3+) (5 mol%) nanophosphor indicates that two set of traps were activated within the temperature range 145 and 215 °C. The kinetic parameters (E,b,s) associated with the prominent glow peaks were estimated using Chen's glow peak shape method. The intensity of the TL glow peak (145 °C) increases linearly with increase of γ-dose upto 1 kGy above which it follows sub-linear behavior. Track interaction model (TIM) was used to explain the linearity/sub linearity/saturation behavior of TL intensity. The TL glow curves show simple glow peak structure, good reusability, low fading and wide range of linearity. Hence, the optimized ZnAl2O4:Ce(3+) (5 mol%) nanophosphor was quite useful for radiation dosimetry and display applications.
authors: Prof. C.N.R. Rao Centre for Advanced Materials, Tumkur University, Tumkur 572 103, India.
authors: B S
authors: BS
authors: Ravikumar
authors: Prof. C.N.R. Rao Centre for Advanced Materials, Tumkur University, Tumkur 572 103, India. Electronic address: bhushanvlc@gmail.com.
authors: H
authors: H
authors: Nagabhushana
authors: B.S. Narayan Centre of Excellence for Advanced Materials, B.M.S. Institute of Technology, Yelahanka, Bangalore 560 064, India; Department of Mechanical Engineering, B.M.S. Institute of Technology, Yelahanka, Bangalore 560 064, India.
authors: S C
authors: SC
authors: Sharma
authors: Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, India.
authors: B M
authors: BM
authors: Nagabhushana
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D002563:Cerium / Q000737:chemistry*; D003080:Cold Temperature; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry*; D008163:Luminescent Measurements; D053758:Nanoparticles / Q000737:chemistry*; D010087:Oxides / Q000138:chemical synthesis / Q000737:chemistry*; D010316:Particle Size; D013819:Thermoluminescent Dosimetry; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry*
chemical_list: D049408:Luminescent Agents; D010087:Oxides; D002563:Cerium; D000535:Aluminum; D015032:Zinc
keywords: Combustion synthesis; Phosphor; Photoluminescence; Thermoluminescence