Structural analyses of Gd3(Al,Ga)5O12 garnet solid solutions via X-ray and UV absorption spectroscopy experiments for Gd atoms
Structural analyses of Gd3(Al,Ga)5O12 garnet solid solutions via X-ray and UV absorption spectroscopy experiments for Gd atoms
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通过 Gd 原子的 X 射线和紫外吸收光谱实验对 Gd3(Al,Ga)5O12 石榴石固溶体进行结构分析
DOI：
10.1016/j.jallcom.2021.159055
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发表时间：
2021
影响因子：
6.2
通讯作者：
Usuki Takeshi
中科院分区：
文献类型：
--
作者：
Kitaura Mamoru;Kamada Kei;Ina Toshiaki;Yamane Hisanori;Ishizaki Manabu;Watanabe Shinta;Azuma Junpei;Yamamoto Isamu;Ohnishi Akimasa;Usuki Takeshi
通过X射线和紫外吸收光谱实验研究了用提拉法生长的Gd3(Al，Ga)5O12石榴石固溶体中Gd原子的低温局域结构。根据Gd K边扩展X射线吸收精细结构(EXAFS)振荡的傅里叶变换(FT)，分别将Ga和Al原子的择优占位分配给了24d和16as位。通过对反傅立叶变换的拟合，确定了Gd与邻近原子之间的原子间距和德拜-沃勒因子。相邻O原子的位置涨落缓冲了Ga和Al原子占据相同晶位所引起的局域扭曲。考虑晶场和Gd原子上的库仑斥力，解释了Gd原子4f内跃迁引起的高分辨紫外吸收光谱的变化。
Local structures of Gd atoms in Gd3(Al, Ga)5O12garnet solid solutions, grown using the Czochralski method, have been studied at low temperatures through X-ray and UV absorption spectroscopy experiments. From the Fourier transforms (FTs) of Gd K-edge extended X-ray absorption fine structure (EXAFS) oscillations, the preferential sites for the occupation of Ga and Al atoms were assigned to the 24dand 16asites, respectively. The interatomic distances between Gd and neighboring atoms, and the Debye–Waller factors were determined through the fit to the inverse FTs. Positional fluctuations of neighboring O atoms buffered local distortions induced by the occupation of Ga and Al atoms at the same crystallographic sites. The change in the high-resolution UV absorption spectra due to Gd intra-4f transitions on the Ga content is explained by considering the crystal field and Coulomb repulsion on the Gd atom.