Local microstructure characterization of rare earth-doped PMMA with low-ion content by fluorescence EXAFS

摘要

Fluorescence-extended X-ray absorption fine structure (EXAFS), and emission spectrum and excitation spectrum (ESES) were used to characterize the local structure of rare earth-doped poly(methyl methacrylate)s (Re-PMMAs) with ion concentration of 600-1000 ppm. Fluorescence EXAFS shows that the chemical state of Sm in SmPMMA is the same as that in Sm2O3 and samarium octanoate (SOA), while that of Eu in Eu-PMMA is different from that in Eu2O3 and europium octanoate. ESES also proves the concomitance of Eu2+ with Eu3+ ions in Eu-PMMA. And, the almost identical peak positions of Eu L, with various Eu content suggests the proportions of EU21 to EU3+ are the same in these samples. The simulation of fluorescence EXAFS shows that the first-shell coordination number of Sm3+ in Sm-PMMA is 9.12, and the average first-shell distance around Sm3+ in Sm-PMMA is 2.43 angstrom. (c) 2006 Wiley Periodicals, Inc.