X-ray Absorption Fine Structure Study of the Local Structures of Activator Atoms in Gadolinium(3+) Oxy-Orthosilicate Single Crystal

• Published in: Japanese Journal of Applied Physics 2006-07, Vol.45 (7R), p.5960
• Main Authors: Yagi, Yasuhiro, Usui, Tatsuya, Shimizu, Shigenori, Kurashige, Kazuhisa, Ishibashi, Hiroyuki, Susa, Kenzo, Honma, Tetsuo
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.45.5960

Measurement of X-ray absorption fine structure (XAFS) was applied to cerium(3+)-activated gadolinium(3+) oxy-orthosilicate system in order to estimate the local structure of the dopant atom. The experimental Ce-L III edge spectra of X-ray absorption near edge structures of Gd 2 SiO 5 :Ce and Gd 2 SiO 5 :Ce,Zr indicated that both samples had only the trivalent Ce. The oscillations of extended X-ray absorption fine structures and the patterns of radial structure functions of these examined samples were compared with those of the reference Gd 2 SiO 5 . We found that Ce substitutes for Gd at the Gd sites in the matrix of the Gd 2 SiO 5 crystal structure, although we could not proceed further than to show a possibility of Zr substitution at the Gd site. From the analysis using the FEFF simulation of Ce-K edge XAFS, it was revealed that Ce substitutes for Gd uniformly at the two Gd sites in the Gd 2 SiO 5 crystal structure. We performed these experiments at the SPring-8, and succeeded in detecting the signals from the low-concentrated elements such as Ce and Zr in this system.