Absorption, Photoluminescence And Thermoluminescence Studies Of γ- Irradiated Pure And Eu Doped LiF phosphors

¹Center for Material Science & Engineering, National Institute of Technology, Hamirpur, India

²Department of Physics, National Institute of Technology, Hamirpur, India

³Department of Physics, Government College, Hamirpur, India

⁴Beant College of Engineering & Technology, Gurdaspur Punjab, India

⁵Health Physics Division, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi, India

Adv. Mater. Lett., 2015, 6 (7), pp 620-627

DOI: 10.5185/amlett.2015.5811

Publication Date (Web): Jul 12, 2015

Copyright © IAAM-VBRI Press

E-mail: sksharma1564@gmail.com

Abstract

We synthesized single phase pure and Eu doped LiF having micro-cubical morphology by modified co-precipitation method. The complete solid solubility of Eu in LiF has been observed up to 0.04 mol% and afterwards phase segregation started. The absorption spectra of pure and Eu doped LiF revealed the formation of γ-irradiation induced and dose dependent F, M and F3 color centers at room temperature. The concentrations of both F and M color centers calculated by using Smakula’s formula, increased almost ten times for γ- irradiated Eu doped LiF in comparison to γ-irradiated pure LiF. Non irradiated LiF doesn’t show any photoluminescence (PL) signal. However, γ-irradiated LiF showed broad emission peak around 681 nm, which is due to the excitation of F2 color centers. The Eu doped LiF samples exhibit PL emission peaks at 577, 591, 612, 648 and 690-698 nm correspond to Eu³⁺ ion transitions from 5D0 to 7 FJ (J=0,1,2,3,4). The γ-irradiated Eu doped LiF show simultaneous PL emission spectrum of Eu³⁺ ions and radiation induced F2 color centers. Thermoluminescence (TL) glow curves of γ- irradiated LiF and LiF: Eu (0.03 mol %) samples were also investigated and various trapping parameters for were evaluated by using Chen’s peak shape method

Keywords

Color centers, photoluminescence, thermoluminescence, irradiation.