Department of Physics, Baoji University of Arts and Science, Baoji, People's Republic of China.
Spectrochim Acta A Mol Biomol Spectrosc. 2010 Jan;75(1):277-80. doi: 10.1016/j.saa.2009.10.023. Epub 2009 Oct 21.
The relations between the spin Hamiltonian (SH) parameters and crystal structure of Cr(4+):alpha-Al(2)O(3) crystals have been established. On the basis of this, the SH parameters including zero-field splitting parameter D and Zeeman g-factors (g(||) and g(perpendicular)) for Cr(4+) ions in Cr(4+):alpha-Al(2)O(3) crystals, taking into account the spin-spin (SS), spin-other-orbit (SOO) and orbit-orbit (OO) magnetic interactions in addition to the spin-orbit (SO) magnetic interaction, are theoretically investigated using complete diagonalization method (CDM). The theoretical results are in excellent agreement with the experimental ones when the upper three O(2-) ions rotate 0.94 degrees toward [111] axis and the lower three O(2-) ions rotate 0.92 degrees toward it. Hence, the local structure distortion effect plays an important role in explaining the spectroscopic properties of Cr(4+) ions in Cr(4+):alpha-Al(2)O(3) crystals. This study shows that for Cr(4+):alpha-Al(2)O(3) the contributions arising from SS, SOO, and OO interactions to the zero-field splitting (ZFS) parameter D are appreciable, whereas those to g(||) and g(perpendicular) are quite small.
已经建立了 Cr(4+)：α-Al(2)O(3) 晶体的自旋哈密顿（SH）参数与晶体结构之间的关系。在此基础上，考虑到自旋-自旋（SS）、自旋-其他轨道（SOO）和轨道-轨道（OO）磁相互作用以及自旋轨道（SO）磁相互作用，除了自旋轨道（SO）磁相互作用外，Cr(4+)：α-Al(2)O(3) 晶体中 Cr(4+)离子的 SH 参数（包括零场分裂参数 D 和塞曼 g 因子（g(||)和 g(perpendicular))) 使用完全对角化方法（CDM）进行了理论研究。当三个上 O(2-)离子沿[111]轴旋转 0.94 度，三个下 O(2-)离子沿其旋转 0.92 度时，理论结果与实验结果非常吻合。因此，局部结构畸变效应对解释 Cr(4+)：α-Al(2)O(3) 晶体中 Cr(4+)离子的光谱性质起着重要作用。这项研究表明，对于 Cr(4+)：α-Al(2)O(3)，SS、SOO 和 OO 相互作用对零场分裂（ZFS）参数 D 的贡献是可观的，而对 g(||)和 g(perpendicular)的贡献则相当小。
