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

概要

論文の詳細を見る
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-LIII edge spectra of X-ray absorption near edge structures of Gd2SiO5:Ce and Gd2SiO5: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 Gd2SiO5. We found that Ce substitutes for Gd at the Gd sites in the matrix of the Gd2SiO5 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 Gd2SiO5 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.
2006-07-15