EPR of Cu²⁺ in Barium Formate Single Crystal

Abstract Results of an X‐band (≈ 9.3 GHz) EPR study of Cu 2+ doped barium formate single crystal at RT and at LNT show that Cu 2+ enters the host lattice at substitutional Ba 2+ sites as well as at an interstitial site. Both the copper (II) complexes show a low symmetry and low site symmetry effects are evident in EPR at RT. The g and A tensors are non‐coaxial at RT for both the copper complexes, however, they become coaxial at LNT. From experimental EPR data the ground state orbitals are obtained and discussed. The ground states are found to be mainly d with some admixture of d . From the observed g ‐value the energy splitting of the d‐orbitals of the metal ion are also obtained. The angular behaviour of EPR spectra is in conformity with the symmetry class of the host crystal as determined by X‐rays.