Study of TL kinetic parameters of UV and y rays irradiated ATiO_3:Eu~(2+), Yb~(2+) (A = Ca, Ba, Sr) phosphors

摘要

The paper discusses the structural studies and TL kinetics analyses of UV and rays irradiated ATiO(3):Eu2+, Yb2+ (A=Ca, Ba, Sr) phosphors synthesized by conventional solid state reaction technique. The impurity ion concentration of Eu2+, Yb2+ ions varies from 0 to 2mol% for each. The study of crystal structure, phase and lattice parameters is done by XRD analysis. The morphological and topographical studies set forth the irregularity of shape and size of particles in synthesized phosphors along with agglomeration. The thermoluminescent spectral study of UV and gamma irradiated phosphors reveals crucial TL kinetics and electron trapping mechanism. The phosphors possess second order kinetics with very high value of activation energy (3eV). This confirms the trapping of electrons in trap centers with high traps depth. The gamma irradiated phosphors possess low fading characteristics than UV irradiated phosphors. The incorporation of divalent impurity ions in the perovskite host lattice attributes to formation of more number of defects and vacancies. These defects and vacancies act as electron trapping sites or trap centers. These phosphors confirm their competence for sensing and TL mapping applications.