材料期刊网

The electron paramagnetic resonance (EPR) g factors g(x), g(y) and g(z) of the orthorhombic Cu2+ (1) site in fresh PrBa2Cu3O6+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 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 angstrom along c axis and the relative bond length variation of about 0.09 angstrom 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.