MeBeF_4(Me=Ca,Sr,Ba)中钐的价态及光谱  

VALENT STATES AND SPECTRAL CHARAC-TERISTICS OF SAMARIUM IN MeBeF_4 (Me= Ca, Sr, Ba)

作　　者：曹志成[1] 石春山[1] 

机构地区：[1]中国科学院长春应用化学研究所稀土化学与物理开放实验室,长春130022

出　　处：《发光学报》1992年第1期36-40,共5页Chinese Journal of Luminescence

基　　金：国家自然科学基金

摘　　要：讨论了MeBeF_4基质中钐离子的光谱及价态.还原气氛中仅在SrBeF_4和BaBeF_4中观察到了Sm^(2+)的发射.A simple technique for the preparation of powder compounds MeBeF4 (Me = Ca, Sr, Ba) doped with divalent samarium is described. The samarium impurity is introducad as samarium difluoride SmF2, and the phosphors are synthesized with successive firing of 6 hr in a stream of pure hydrogen in the temperature range of 800-900???CCCCCCCC. The data of X-ray diffraction agree with that of references and standard cards .Using this method, samarium has beon stabilized in the divalent state in SrBeF4 and BaBeF4. But in CaBeF4, although in the same synthetic conditions, the emission spectrum of divalent samarium has not been observed either. This indicates that the stability of divalent samarium not only depends on the synthetic conditions but also the composition of the matrix. The data of ESCA indicate that with the increase of the radius of substituted cation, the stability of divalent samarium increases. The emission spectra of Sm2+ and Sm3+ in MeBeF4 are presented and briefly discussed. For the spectra of Sm2+ in SrBeF4 and BaBeF4 its excitation peak is due to the transition absorption of 4f6-4f55d, and the emission peak is due to the transition emission of 5D0-7F7. The transition emission designations of Sm3+ in MeBeF4 are due to4G5/2-8Hj.

关 键 词：磷光体 钐 离子 激发态 价态 光谱 

分 类 号：O614.337[理学—无机化学]