【作者】 杨艳民； 李志强； 陈宝玖；

【Author】 Yanmin Yang~(*1) Zhiqiang Li~1 Baojiu Chen~2 (1 College of Physics Science and Technology,Hebei University,Baoding 071002,China) (2 Department of Physics,Dalian Maritime University,Dalian,1106026,China)

【机构】 河北大学物理科学与技术学院发光与显示研究所； 大连海事大学物理系；

【摘要】 采用共沉淀方法制备了稀土离子Eu³⁺,Dy³⁺,Sm³⁺掺杂的Ca（Sr,Ba）WO₄发光材料,目的是研究金属阳离子改变对稀土离子发光性质的影响。X射线衍射光谱数据表明CaWO₄,SrWG₄,BaWO₄都是四方晶系I41/a（88）结构,随着阳离子半径增加,衍射峰向小角移动。不同温度制备的BaWO₄样品X射线衍射光谱数据表明随着制备温度降低衍射峰展宽,这是由于较低温度制备的样品晶体尺寸较小,随着制备温度提高样品的尺寸增加,样品的SEM照片证实了这一结论。测试了Eu³⁺,Dy³⁺,Sm³⁺掺杂的Ca（Sr,Ba）WO₄发光材料的激发和发射光谱。计算了Eu³⁺掺杂的Ca（Sr,Ba）WO₄的Judd-Ofelt强度参数Ω2,Ω4,Ω2随着阳离子半径增加（Ca-Sr-Ba）迅速减小,它导致Eu³⁺掺杂的Ca（Sr,Ba）WO₄的发射强度随着阳离子半径增加发射峰强度迅速降低。然而Dy³⁺,Sm³⁺掺杂的SrWO₄的发射峰强度较其他两种晶体发射峰反而增加,根据激发光谱和文献报道可能是由于钨酸根离子与稀土离子的能量传递。从Dy³⁺,Sm³⁺掺杂的Ca（Sr,Ba）WO₄的发射光谱可以看到随着阳离子半径增加,发射峰红移,发射峰的Stark劈裂减弱。我们用位形坐标图解释了这一现象产生的原因。更多还原

【Abstract】 Eu³⁺,Dy³⁺,Sm³⁺doped Ca（Sr,Ba）WO₄ phosphors are synthesized by the co-precipitation method in order to investigate the effect of changed metallic cations on optical properties of rare-earth ions Eu³⁺,Dy³⁺,Sm³⁺.The data of X ray diffraction（XRD）indicated that the crystal structure of CaWO₄, SrWO₄,BaWO₄ belong to Tetragonal,I41/a（88）and the diffraction peaks moved towards smaller angle with increasing diameter of the metal cations.The data of X ray diffraction（XRD）of BaWO₄ synthesized by different temperatures showed that the diffraction peaks were broaden with lower synthesized temperature,which can be attributed to the small particle radius（about 100nm seen from SEM morphology）of BaWO₄ with lower synthesized temperature.The emission spectrum and excitation spectrum of Eu³⁺,Dy³⁺,Sm³⁺doped Ca（Sr,Ba）WO₄ phosphors were measured.Judd-Ofelt strength parameters of Eu³⁺ion,Ω2,Ω4 were calculated.The data indicated thatΩ2 decreased with increasing diameter of the metal cations which can be used to explain the fallen light emission of Eu³⁺doped Ca（Sr, Ba）WO₄ with increasing diameter of the metal cations.However,the emission intensity of Dy³⁺,Sm³⁺doped SrWO₄ phosphors are more stronger than Dy³⁺,Sm³⁺doped Ca（Ba）WO₄ which can be explained by the energy transfer between of WO₄^-2and rare earth ions.It can be seen from the emission spectrum of Dy³⁺,Sm³⁺doped Ca（Sr,Ba）WO₄ phosphors the emission peaks moved towards longer wavelength and the emission peaks of Stark levels are close to each other,which is explained by the configurational coordinate diagram.更多还原