Investigations of the EPR g factors for tetragonal copper site in Sr2Ca2Cu3Ox

Abstract

The electron paramagnetic resonance (EPR) [Formula: see text] factors are quantitatively investigated for tetragonal [Formula: see text] site in [Formula: see text] by utilizing the perturbation formulas of the [Formula: see text] factors for a tetragonally elongated octahedral [Formula: see text] cluster from the cluster approach. The anisotropy of the [Formula: see text] factors is discussed from the local tetragonal elongation of this five-fold coordinated copper site. The present EPR analysis for this precursor of Hg-1223 superconductors can be useful to the understandings of the relationships between the local structure (significant elongation of the copper site) and the intense Cu–O orbital hybridization and hence the high [Formula: see text] of the Hg-1223 systems.