Spin-Hamiltonian parameters and tetragonal distortion due to the Jahn–Teller effect for Cu²⁺ centres in trigonal Zn(BrO₃)·6H₂O crystal

Abstract

The spin-Hamiltonian parameters (g factors g_//, g_⊥ and hyperfine structure constants ⁶⁵A_// and ⁶⁵A_⊥) for the tetragonal Cu²⁺ centres in trigonal Zn(BrO₃)·6H₂O crystal are calculated from the complete diagonalization (of energy matrix) method (CDM) based on the cluster approach. In the CDM, the Zeeman and hyperfine interaction terms are added to the Hamiltonian in the conventional CDM and the contributions to the spin-Hamiltonian parameters from both the spin-orbit coupling parameter of central d⁹ ion and that of ligand ion are included. The calculated spin-Hamiltonian parameters of Zn(BrO₃)·6H₂O: Cu²⁺ show good agreement with the experimental values and the tetragonal elongation (characterized by ΔR=R_// − R _⊥, where R_// and R _⊥ represent the metal-ligand distances parallel with and perpendicular to the C₄ axis) due to the static Jahn–Teller effect is obtained from the calculations. The results are discussed.

Keywords:

• electron paramagnetic resonance
• crystal- and ligand-field theory
• Jahn–Teller effect
• defect structure
• Cu²⁺, Zn(BrO₃)·6H₂O

Acknowledgements

This project was supported by the Education Committee Natural Science Foundation of Chongqing (KJ090608) and the Scientific Research Foundation of Chongqing University of Technology of China (2008ZQ12 and 2009ZD09).