Investigations of the g factors and local structure for orthorhombic Cu^{2+}(1) site in fresh PrBa_{2}Cu_{3}O_{6+x} powders

TL;DR

This study theoretically investigates the electron paramagnetic resonance g factors of Cu^{2+} in orthorhombic PrBa_{2}Cu_{3}O_{6+x} powders, linking local structural distortions to magnetic properties.

Contribution

It introduces a theoretical approach to relate local Jahn-Teller distortions to EPR g factors in orthorhombic Cu^{2+} sites, using perturbation formulas and the superposition model.

Findings

The Cu^{2+} site experiences axial elongation of about 0.04 Å.

Bond length variations of about 0.09 Å are observed along a and b axes.

Theoretical g factors agree reasonably with experimental data.

Abstract

The electron paramagnetic resonance (EPR) g factors g_x, g_y and g_z of the orthorhombic Cu^{2+}(1) site in fresh PrBa_{2}Cu_{3}O_{6+x} powders are theoretically investigated using the perturbation formulas of the g factors for a 3d^9 ion under orthorhombically elongated octahedra. The local orthorhombic distortion around the Cu^{2+}(1) site due to the Jahn-Teller effect is described by the orthorhombic field parameters from the superposition model. The [CuO6]^{10-} complex is found to experience an axial elongation of about 0.04 {\AA} along c axis and the relative bond length variation of about 0.09 {\AA} along a and b axes of the Jahn-Teller nature. The theoretical results of the g factors based on the above local structure are in reasonable agreement with the experimental data.