Spin-Hamiltonian parameters and zero-field splitting of impurity Gd3+ ions in SrY2O4 crystal

Electron paramagnetic resonance (EPR) study of the impurity Gd3+ ions in the multi-site SrY2O4 crystal isostructural to the magnetically-frustrated SrGd2O4 compound is reported. Analysis of the angular dependences of the EPR spectra at room temperature allowed us to establish the spin-level energy patterns in the ground states of the Gd3+ ions at the Y(1) and Y(2) sites. Parameters of the spin-Hamiltonian in the frames related to the crystal axes and to the principal center axes are determined.