2003年12月
Importance of fourth-order zero-field splitting terms in random-orientation EPR spectra of Eu(II)-doped strontium aluminate
JOURNAL OF PHYSICAL CHEMISTRY A
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- 巻
- 107
- 号
- 51
- 開始ページ
- 11539
- 終了ページ
- 11546
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/jp030819
- 出版者・発行元
- AMER CHEMICAL SOC
This work discusses an issue caused by omitting the fourth-order zero-field splitting (ZFS) terms in the analysis of random-orientation EPR spectra. Eu(II)-doped strontium aluminates were employed as a model system of the S-state lanthanoid ions, which have relatively large second-rank ZFS components, comparable to the conventional X-band microwave energy. The initial estimation of second- and fourth-rank ZFS components was acquired uniquely from the W-band spectrum based on a perturbation treatment of the spin Hamiltonian, and they were refined by a hybrid-eigenfield simulation approach. A parallel simulation of the X- and W-band spectra with the refined parameters reasonably reproduced both the observed spectra. The reliability of the parameters was also verified by reproducing the off-principal-axis extra lines arising from the M-S = 1/2 <----> 1/2 transition observed in the W-band spectrum. By comparison with an analysis based on the spin Hamiltonian omitting the fourth-order terms, it was concluded that omitting these terms results in an erroneous determination of the rhombic parameter (E) of the second-rank ZFS tensor. The obtained reliable second-rank ZFS tensors enabled us to invoke the superposition model, determining their principal-axis orientation. This is the first report of such relative orientation determined for Eu(II)-doped strontium aluminates.
- リンク情報
- ID情報
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- DOI : 10.1021/jp030819
- ISSN : 1089-5639
- Web of Science ID : WOS:000187446900034