Investigations of the g factors and local structure for orthorhombic Cu2+(1) site in fresh PrBa2Cu3O6+x powders

The electron paramagnetic resonance (EPR) g factors gx, gy and gz of the orthorhombic Cu2+(1) site in fresh PrBa2Cu3O6+x powders are theoretically investigated using the perturbation formulas of the g factors for a 3d9 ion under orthorhombically elongated octahedra. The local orthorhombic distortion around the Cu2+(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 along c axis and the relative bond length variation of about 0.09 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.