Influence of thermal treatment on OSL regeneration in potassium chloride

Optically stimulated luminescence (OSL) of pure analytical potassium chloride (KCl) prepared in two different forms (crystals and pellets) was studied. The occurrence of regeneration effect (self-renewal of the OSL signal) in the material was examined. The experiments using the variable delay OSL (VD-OSL) method were carried out. Performed measurements allowed to determine time scale of the phenomenon, as well as quantitative changes of regeneration depending on thermal treatment before and after irradiation. Significant increase of the OSL regeneration was noticeable for pellets after the application of the annealing before irradiation, while for crystals a substantial decrease of regeneration was observed. Preheating applied after irradiation caused that self-renewal of OSL signal was drastically reduced or completely suppressed depending on the form of KCl samples.     

Zn元素替代对MgGa2O4∶Cr3+的结构和发光性能的影响

采用高温固相法按化学式Zn_xMg_(1-x)Ga₂O₄∶Cr3+(x=0,0.2,0.6,0.8,1.0)配比原料制备了一系列红色长余辉发光材料。X射线衍射(XRD)分析表明样品物相均为面心立方结构。光致发光特性表明样品的红光发射峰均由以Cr3+为发光中心的电子2E—4A₂跃迁所致,Cr3+的激发带与基质发射带之间有大面积重叠,两者间存在有效的能量传递。余辉衰减曲线与热释光谱分析表明,不同Zn掺入量的样品余辉衰减快慢不同,是由于其中存在的陷阱能级深度不同,且陷阱能级越深,其余辉时间越长。     

Trapping and self-trapping in ytterbium-doped oxides with charge transfer luminescence

Temperature dependence of the charge transfer luminescence (CTL) of Yb-doped yttrium aluminum garnet Y₃Al₅O₁₂-Yb (YAG-Yb) and Yb-doped lutetium aluminum perovskite LuAlO₃-Yb (LuAP-Yb) crystals under X-ray excitation and their thermostimulated luminescence are investigated in the temperature range 30-350 K and compared to those of undoped crystals. Simulation using a set of kinetic equations describing the processes of creation of excitons, electron-hole pairs, their trapping and self-trapping, radiative relaxation and quenching is presented for the systems under investigation to analyze qualitatively two different types of experimentally observed temperature dependences: CTL yield decline with the temperature decrease below 110 K as in case of YAG-Yb and constant yield in the same temperature range as in case of LuAP-Yb.