Thermoluminescence Kinetic Parameters and Radioluminescence of RE3+ (RE = Pr, Sm, Tb, Ho, Er)-Doped Barium Tantalate Phosphors

Keskin, IÇ; Ilhan, M

Thermoluminescence Kinetic Parameters and Radioluminescence of RE3+ (RE = Pr, Sm, Tb, Ho, Er)-Doped Barium Tantalate Phosphors

Authors

Keskin, IÇ

Ilhan, M

Publisher

SPRINGER

Abstract

The thermoluminescence (TL) kinetic parameters and radioluminescence results (RL) of RE3+ (RE = Pr, Sm, Tb, Ho, Er)-doped barium tantalate phosphors have been studied for different concentrations. The concentration quenching occurring at the RL intensity of Pr3+ after 1.5 mol% was associated with a cross-relaxation between P-3(0) -> H-3(4) and D-1(2) -> H-3(4), while the RL emissions of Tb3+ were observed corresponding to transitions of(5)D(4) -> F-7(J). The asymmetry ratio of RL is relatively high compared to the PL asymmetry ratio for Sm3+, which may be attributed to the RL mechanism leading to some decrease in the local symmetry of Sm3+ ions. The Ho3+ and Er3+ show the characteristic green and red emissions corresponding to radiative transitions. Also, the spectral properties of the phosphors have been discussed by comparing the RL results, the reported PL results of Pr3+, Sm3+, Ho3+, Er3+ , and the PL results of Tb3+ , which were examined in the study. After being irradiated by x-ray and short-wave UV light (254 nm), TL glow curves for Pr3+, Tb3+, and Er3+ doped phosphors were compared in the range of 50 degrees C and 400 degrees C at a heating rate of 2 degrees C s(-1). TL glow peaks for Pr3+, Tb3+, and Er3+ formed at temperatures of 77 degrees C and 208 degrees C, 87 degrees C and 263 degrees C, and 158 degrees C and 267 C, respectively. The kinetic data were estimated by applying computerized glow curve deconvolution (CGCD) where TL glow curves of BaTa2O6:RE3+ (RE = Pr, Tb, Er) consist of 5, 6, and 7 estimated glow peaks with figure-of-merit values of 1.06, 1.60, and 1.09, respectively.