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XANES Spectroscopic Studies of the Phase Transition in Gd 2 Zr 2 O 7
Author(s) -
Lee YuHsuen,
Chen JinMing,
Lee JyhFu,
Kao HueyChuen I.
Publication year - 2009
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.200900080
Subject(s) - chemistry , xanes , analytical chemistry (journal) , k edge , absorption spectroscopy , absorption edge , crystallography , absorption (acoustics) , crystal (programming language) , spectral line , pyrochlore , phase (matter) , atomic physics , band gap , materials science , physics , organic chemistry , chromatography , astronomy , computer science , composite material , programming language , optoelectronics , quantum mechanics
The structural phase transition from fluorite to pyrochlore and the strength of the coordination bond of Zr–O in Gd 2 Zr 2 O 7 were investigated by XANES spectra of both O and Zr K ‐edge. The energy difference of the O K ‐edge absorption spectra at 532 and 536 eV was assigned to the crystal field splitting energy of the 4d orbital (Δ E 4d , t 2g and e g ) of the Zr ion. Also, in the samples prepared at higher temperatures, the 536 eV peak moves slightly to higher energy, whereas the absorption energy of 532 eV peak does not shift. A correlation between Δ E 4d and the strength of interaction between Zr (4d) and O (2p) orbitals has been found. Furthermore, two Zr K ‐edge absorptions at 18020 and 18030 eV of Gd 2 Zr 2 O 7 have been observed; the splitting energy (Δ E ), peak intensity ratio ( I 18030 / I 18020 ), and FWHM of the first derivative of the absorption curve depend on the preparation temperatures. The effect of crystal symmetry and Zr‐O bonding character on the XANES spectral profile was discussed.