Studies on the local structures and the spin Hamiltonian parameters for Fe3+ in CdX (X = S,Se, Te) |
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Authors: | Xian-Fen Hu Shao-Yi Wu Min-Quan Kuang Guo-Liang Li Chang-Chun Ding |
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Institution: | 1. Department of Applied Physics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, P.R. China;2. Department of Physics, School of Science, Southwest University of Science and Technology of China, Mianyang, P.R. Chinaxfhu117@163.com |
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Abstract: | The improved perturbation formulas of the spin Hamiltonian parameters (zero-field splitting D and g factors) for a 3d5 ion in trigonally distorted tetrahedra are constructed from the cluster approach by including both the crystal-field and charge-transfer contributions. These formulas are applied to the studies of the local structures and the electron paramagnetic resonance (EPR) spectra for Fe3+ in CdX (X = S, Se, Te). The impurity Fe3+ is found not to occupy exactly the host Cd2+ sites but to experience the small outward shifts 0.014 and 0.006 Å away from the ligand triangles along the C3 axis in CdS and CdSe, respectively. The charge-transfer contributions to the spin Hamiltonian parameters are important and increase significantly with increasing atomic number of the ligand (i.e., S2? < Se2? < Te2?) arising from the decreases of charge-transfer energy levels and the increases of ligand spin–orbit coupling coefficients. The results are discussed. |
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Keywords: | defect structures electron paramagnetic resonance (EPR) Fe3+ CdX (X = S Se Te) |
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