Theoretical evaluation of the electron paramagnetic resonance spin Hamiltonian parameters for the impurity displacements for Fe3+ and Ru3+ in corundum

摘要

The impurity displacements for Fe3+ and Ru3+ in corundum (Al2O3) are theoretically studied using the perturbation formulas of the spin Hamiltonian parameters (zero-field splitting and anisotropic e?‘” factors) for a 3d5 (with high spin e?‘? = 5/2) and a 4d5 (with low spin e?‘? = 1/2) ion in trigonal symmetry, respectively. According to the investigations, the nd5 (e?‘? = 3 and 4) impurity ions may not locate at the ideal Al3+ site but undergo axial displacements by about 0.132 ?… and 0.170 ?… for Fe3+ and Ru3+, respectively, away from the center of the ligand octahedron along the C3 axis. The calculated spin Hamiltonian parameters based on the above axial displacements show good agreement with the observed values. The validity of the results is discussed.