Investigation of the adiabatic potential relief in single crystals with copper ions

Complex study of ESR spectra of Cu²⁺ ions implanted into the single crystals of LiGa₅O₈ inverse spinel and ZnWO₄ zinc tungstate has been performed. The ESR-spectra are interpreted by using the a modified crystal field theory. It is found that the adiabatic potential of the Cu²⁺ ion in LiGa₅O₈ is multi-minimum one, whereas the adiabatic potential of a Cu²⁺ ion in ZnWO₄ has a single minimum. It is shown that the existence of a low-symmetry distortion leads to the frustration suppression and, eventually, to the formation of a global minimum of the adiabatic potential