Transparent long lasting and photo-stimulating materiaals

在用Tb3+离子活化的还原铝酸钙玻璃中发现了长余辉发光(LLL)和光激励发光(PSL)。用紫外光照射Tb3+的4f-5d电荷转移带，观察到Tb3+的低发光，而用633 nm的紫外光刺激玻璃，观察到PSL。LLL的衰减曲线在初始阶段符合二级动力学，在后一阶段符合一级动力学。在紫外光照射下，产生了电子自旋共振信号，其强度衰减与LLL的后一组分相吻合。在633 nm光照射下，PSL的出现明显降低了ESR信号的强度。样品在77K下的热释光光谱由~240K和~380K两个峰组成，低温峰和高温峰分别由一个F中心(两个电子捕获在氧空位)和一个F+中心(一个电子捕获在氧空位)组成。结果表明，F中心的电子和F+中心的电子分别对LLL和PSL的产生起主要作用。

Long lasting luminescence(LLL)and photostimulated luminescence(PSL)were found in reduced calcium aluminate glasses activated with Tb3+ ions. The LLL from Tb3+ was observed by illuminating the Tb3+4f-5d charge transfer band with uv light, while the PSL was seen by stimulating the glasses after uv-illumination with 633nm light. The decay curve of the LLL was fitted with a second order kinetics for the initial period and a first order for the latter. An electron spin resonance signal which is attributed to an F+-like center associated with Ca^<2+> ions was induced by illumination with uv-light and its intensity decay was fitted with the latter component of the LLL.The appearance of the PSL by illumination with 633nm light distinct reduced the ESR signal intensity. The thermoluminescent spectra of the specimen illuminated at 77K were composed of two components peaking at 〜240K and 〜380K.The low temperature peak and the high temperature peak were attributed to an F-center(two electrons trapped at the site of an oxygen vacancy)and an F+-center(an electron trapped at the site of an oxygen vacancy), respectively. It was concluded from the above results that electrons of the F-center and the F+-center contribute predominantly to the emergence of the LLL and the PSL, respectively.