Theoretical investigations of the spin Hamiltonian parameters and local tetragonal distortions for Cu2+ in crystalline and amorphous TeO2 and GeO2 |
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Authors: | Xian-Fen Hu Shao-Yi Wu Guo-Liang Li Zhi-Hong Zhang |
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Institution: | Department of Applied Physics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, P.R. China |
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Abstract: | The spin Hamiltonian parameters (i.e., anisotropic g factors and hyperfine structure constants) and local tetragonal distortions for Cu2+ in crystalline and amorphous TeO2 and GeO2 are theoretically investigated using the high-order perturbation formulas of these parameters for a tetragonally elongated octahedral 3d9 cluster. The impurity Cu2+ occupying the octahedral sites are found to experience the relative tetragonal elongation ratios of about 11.4% and 9.5% for crystalline TeO2 and GeO2 and 10.8% and 6.6% for amorphous TeO2 and GeO2, respectively, along the C4 axis due to the Jahn–Teller effect. This reveals the larger tetragonal elongation distortions for the Cu2+ centres in crystalline than amorphous systems (especially TeO2). The theoretical spin Hamiltonian parameters show good agreement with the experimental data. The results are discussed. |
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Keywords: | electron paramagnetic resonance defect structures Cu2+ TeO2 GeO2 |
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