Investigations on the spin Hamiltonian parameters for Yb3+ ion in Bi2Sr2YCu2O8

Highlights: • The EPR spectra are studied for the two orthorhombic Yb3+ centers in Bi2Sr2YCu2O8. • The contributions due to the admixtures of various states are taken into account. • The spin Hamiltonian parameters show good agreement with experimental data. -- Abstract: Many theoretical and experimental works have been done to understand the several characteristics of the Bi2Sr2YCu2O8. Since the electron paramagnetic resonance (EPR) is a powerful tool to analyze the electronic and magnetic properties of paramagnetic impurities in compounds, studies on the above EPR parameters would be helpful to the investigations of the characteristics for the superconductors. In this paper, EPR parameters anisotropic g factors gx, gy, gz, and the hyperfine structure constants Ax, Ay and Az of the two orthorhombic Yb3+ centers in Bi2Sr2YCu2O8 are theoretically studied from the perturbation formulas of these parameters for a 4f13 ion in orthorhombic symmetry. In these formulas, the contributions due to the admixtures of various states are taken into account, and the orthorhombic field parameters are obtained from the superposition model and the local structure of the impurity Yb3+ ion occupying the host Bi3+ site. The calculated EPR parameters are reasonable agree with the observed values