Electron paramagnetic resonance parameters and local structure for Gd3+ in KY3F10

Abstract

The electron paramagnetic resonance parameters, zero-field splittings (ZFSs) b 0 2 , b 0 4 , b 4 4 , b 0 6 , b 4 6 and the g factors for Gd 3+ on the tetragonal Y 3+ site in KY3F10 are theoretically studied from the superposition model for the ZFSs and the approximation formula for the g factor containing the admixture of the ground 8 S 7/2 and the excited 6 L 7/2 (L=P, D, F, G) states via the spin-orbit coupling interactions, respectively. By analysing the above ZFSs, the local structure information for the impurity Gd 3+ is obtained, i.e., the impurity-ligand bonding angles related to the four-fold (C4) axis for the impurity Gd 3+ center are found to be about 0.6 • larger than those for the host Y 3+ site in KY3F10. The calculated ZFSs based on the above angular distortion as well as the g factors are in reasonable agreement with the observed values. The present studies on the ZFSs and the local structure would be helpful to understand the optical and magnetic properties of this material with Gd dopants.

EPR Study of Gd3+local structure in ScF3crystal with negative thermal expansion coefficient

“…Semi-empirical superposition model (SM) has been used extensively for Gd 3+ ZFS parameter calculations in different crystals [12,13,[24][25][26][27][28]. It states that crystal field at a paramagnetic centre can be calculated from the sum of contributions from neighbouring ligands.…”