Studies of the EPR Parameters and Local Structure for the Cu2+ Center in Lanthanum Magnesium Nitrate
The electron paramagnetic resonance parameters (g-factors and the hyperfine structure constants) for the Cu2+ center in lanthanum magnesium nitrate (LMN) are theoretically studied from the conventional perturbation formulas of these parameters for a 3d9 ion in tetragonally elongated octahedra. The studied complex is found to exhibit the slight tetragonal elongation (characterized by the relative elongation ratio ρ 4%) due to the Jahn-Teller effect, which may entirely conceal the original trigonal distortion of the host Mg2+ site in LMN. The conventional formulas containing only the metal orbital and spin-orbit coupling contributions are proved to be valid for the Cu2+ center in view of the weak covalency and ligand spin-orbit coupling interactions. This defect is also compared with the similar Cu2+ center of the Jahn-Teller nature on the octahedral interstitial site in the CdSe nanocrystals.
David J. Fisher
M. Q. Kuang et al., "Studies of the EPR Parameters and Local Structure for the Cu2+ Center in Lanthanum Magnesium Nitrate", Defect and Diffusion Forum, Vols. 305-306, pp. 85-88, 2010