title: Radiation-induced defects in manganese-doped lithium tetraborate phosphor.
abstract: Lithium tetraborate doped with manganese synthesised by solid-state sintering technique exhibits a dosimetric peak at 280°C. The high-temperature glow curve results in no fading for three months. The sensitivity of Li2B4O7:Mn is determined to be 0.9 times that of TLD-100. The infrared spectrum of this phosphor indicates the presence of bond vibrations corresponding to BO4 tetrahedral and BO3 triangles. The mechanism for thermoluminescence in this phosphor was proposed based on the thermoluminescence (TL) emission spectra, kinetic analysis of TL glow curves and electron paramagnetic resonance (EPR) measurements on non-irradiated and gamma-irradiated phosphors. It was identified that oxygen vacancies and Boron oxygen hole centre (BOHC) are the electron and hole trap centres for TL in this phosphor. When the phosphor is heated, the electrons are released from the electron trap and recombine with the trapped holes. The excitation energy during the recombination is transferred to the nearby Mn(2+) ions, which emit light at 580 nm.
authors.affiliation: Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India.
authors.forename: O
authors.initials: O
authors.lastname: Annalakshmi
authors.affiliation: Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India mtj@igcar.gov.in.
authors.forename: M T
authors.initials: MT
authors.lastname: Jose
authors.affiliation: Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India.
authors.forename: U
authors.initials: U
authors.lastname: Madhusoodanan
authors.affiliation: Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai, India.
authors.forename: J
authors.initials: J
authors.lastname: Sridevi
authors.affiliation: Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India.
authors.forename: B
authors.initials: B
authors.lastname: Venkatraman
authors.affiliation: Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India.
authors.forename: G
authors.initials: G
authors.lastname: Amarendra
authors.affiliation: Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai, India.
authors.forename: A B
authors.initials: AB
authors.lastname: Mandal
mesh_terms: D001881:Borates / Q000737:chemistry / Q000528:radiation effects; D004578:Electron Spin Resonance Spectroscopy; D005720:Gamma Rays; D006801:Humans; D008094:Lithium / Q000737:chemistry / Q000528:radiation effects; D008163:Luminescent Measurements / Q000379:methods; D008345:Manganese / Q000737:chemistry / Q000528:radiation effects; D013055:Spectrophotometry, Infrared; D013819:Thermoluminescent Dosimetry / Q000379:methods*
chemical_list: D001881:Borates; D008345:Manganese; C021755:tetraborate; D008094:Lithium