摘要
在空气中采用高温固相反应方法合成的17MO (8 x y)La2O3 75B2O3 xEu2O3 yGd2O3(MLBEG,M=Mg,Ca,Sr,Ba)玻璃,在紫外光(λex=350nm)激发下发射蓝光和红光,在绿色光(λex=532nm)激发下发射红光。电子自旋共振谱研究表明玻璃体系中有Eu2+离子存在。蓝色区的宽带发射是Eu2+离子的5d 4f跃迁发射;红色区的窄带发射是Eu3+离子的5D0 7FJ(J=1,2,3,4)跃迁发射。发现玻璃中的碱土金属离子对Eu3+ Eu2+离子的比例有很大影响。选择不同的碱土金属离子可以调节玻璃蓝色光和红色光的相对发射强度。MLBEG玻璃的发光性质可用于转换太阳能,增强植物的光合作用。
17MO(8xy)La2O375B2O3xEu2O3yGd2O3(MLBEG, M= Mg, Ca, Sr, Ba) glasses were prepared with the conventional high temperature process. The study of luminescent spectra and ESR reveals that in this system, there have existed two valence states for europium ions: Eu2+ and Eu3+. The broad emission band peaking at 430 nm correspond to the 5d→4f emission transition of Eu2+ ions, the sharp emission bands peaking at 592, 616, 650 and 750 nm correspond to the 5D0→7FJ (J=1,2,3,4,) emission transition of Eu3+ ions respectively. In these borate glasses networks, the kind of alkaline earth ions determine the amount of Eu2+ ions reduced from Eu3+ ions under the ambient atmosphere. So, the relative emission intensity of blue and red component of the glass should be controlled by different alkaline earth ions. The experimental results show that the introduction of Gd3+ ion can distinctly improve the emission intensity ratios of the blue light and red light of the glass, which indicates that the main process of energy transfer is Gd3+→Eu2+→Eu3+ in MLBEG system. The lightconversion properties of MLBEG glasses may be applied in making fully use of solar energy to increasing photosynthesis of plants.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2002年第6期620-624,共5页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金资助项目(20071011)
