title: Thermoluminescence of MgSO4 doped with Eu and P impurities.
abstract: CaSO4:Eu, MgSO4:Eu and MgSO4:Eu,P phosphors have been prepared and their thermoluminescence (TL) characteristics were studied. A main glow peak due to Eu2+ ions is seen at approximately 146 degrees C and 440 nm and glow peaks at approximately 145 degrees C, approximately 190 degrees C, approximately 260 degrees C and approximately 360 degrees C for 590 nm and 625 nm wavelengths are identified as Eu3+ ion emissions in MgSO4:Eu. Emission spectra in MgSO4:Eu and the MgSO4:Eu,P show that the MgSO4:Eu3+ glow peak at 260 degrees C for 590 nm and 625 nm shifts to 280 degrees C with enhanced intensity while the Eu2+ ion glow peak at 146 degrees C remains but with reduced intensity. The main glow peak at approximately 146 degrees C and 440 nm from Eu2+ ions shows significant difference from the characteristic glow peaks of Eu3+ ions. It is observed that the wavelength of the Eu2+ ion glow peak is inversely proportional to the radius of the cation of the host sulphate in alkaline-earth sulphate phosphors. By contrast the wavelengths of the Eu3+ ion glow peaks remain unchanged in different sulphates. Besides, the glow curve at approximately 146 degrees C obtained using a conventional blue sensitive reader shows simply the first order kinetics. It is concluded that the luminescence centres and distribution of traps related to Eu2+ ions are different from that of Eu3+ ions in MgSO4:Eu and MgSO4:Eu,P phosphors.
authors.affiliation: Department of Physics, Zhongshan University, Guangzhou, PR China. stszcx@zsu.edu.cn
authors.forename: C X
authors.initials: CX
authors.lastname: Zhang
authors.forename: Q
authors.initials: Q
authors.lastname: Tang
authors.forename: D L
authors.initials: DL
authors.lastname: Luo
authors.forename: Z R
authors.initials: ZR
authors.lastname: Qiu
authors.forename: P L
authors.initials: PL
authors.lastname: Leung
authors.forename: M J
authors.initials: MJ
authors.lastname: Stokes
mesh_terms: D005063:Europium / Q000737:chemistry; D005720:Gamma Rays; D006358:Hot Temperature; D007700:Kinetics; D008163:Luminescent Measurements; D008278:Magnesium Sulfate / Q000737:chemistry / Q000528:radiation effects*; D010758:Phosphorus / Q000737:chemistry; D011854:Radiochemistry; D013053:Spectrophotometry; D013819:Thermoluminescent Dosimetry / Q000379:methods* / Q000706:statistics & numerical data
chemical_list: D010758:Phosphorus; D005063:Europium; D008278:Magnesium Sulfate