Theoretical Studies of the Zero-Field Splitting and g Factor for Gd3+ in La2-xSrxCuO4
Abstract
The zero-field splitting D of the 8S7/2 ground singlet for the tetragonal Gd3+ center in La2-xSrxCuO4 is theoretically studied from the superposition model. Meanwhile, the g factor is also quantitatively investigated from the approximation formula including admixture of the ground 8S7/2 and the excited 6L7/2 (L=P, D, F, G) states via the spin-orbit coupling interactions. The calculated zero-field splitting and g factor are in reasonable agreement with the experimental data. It is found that the significant zero-field splitting can be ascribed to the average impurity-ligand bonding angles [≈ (θ1 + θ2)/2 ≈ 62°] related to the four-fold axis larger than that (≈ 54.74°) of the cubic case. Nevertheless, the experimental g factor close to 2 may be largely due to the very slight admixture of the ground 8S7/2 and the excited 6L7/2 states via the spin-orbit coupling interactions.
- Publication:
-
International Journal of Modern Physics B
- Pub Date:
- 2007
- DOI:
- 10.1142/S0217979207044317
- Bibcode:
- 2007IJMPB..21.3254W
- Keywords:
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- Crystal fields and spin Hamiltonians;
- EPR;
- Gd3+;
- La2-xSrxCuO4