Multiple thermoluminescence glow peaks and afterglow suppression in CsI:Tl co-doped with Eu2+ or Yb2+

[摘要] CsI:Tl is a widely utilized scintillator material with many desirable properties but its applicability is limited by persistent afterglow. However, effective afterglow suppression has been achieved by co-doping with divalent lanthanides. The present report is concerned with observation of multiple thermoluminescence glow peaks in CsI:Tl,Eu and CsI:Tl,Yb, attributed to varying distributions of charge-compensating cation vacancies relative to divalent lanthanide co-dopants, and the subsequent modification of these distributions by repeated observations. It is observed that Yb2+provides a slightly shallower electron trap than Eu2+, and that it can occupy a face-centered position by virtue of its relatively small ionic radius; the latter observation is confirmed by electrostatic calculations. It is also found that repeated observation of thermoluminescence in these materials has a modest adverse effect on afterglow suppression.

[发布机构] Department of Physics, University of Connecticut, Storrs; CT; 06269, United States^1;Alem Associates, 44 Hunt St., Watertown; MA; 02472, United States^2;Radiation Monitoring Devices, 44 Hunt St., Watertown; MA; 02472, United States^3

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Adverse effect;Afterglow suppression;Charge-compensating cations;Divalent lanthanides;Electrostatic calculations;Glow peaks;Ionic radius;Scintillator materials