Single crystal EPR and optical absorption studies of Cu2+ ion in l-arginine sulphophosphate monohydrate-a nonlinear optical crystal

The EPR spectra of Cu2+ ion in l-arginine sulphophosphate monohydrate (LASP), a nonlinear optical material (NLO) have been studied at room temperature. Two magnetically inequivalent interstitial Cu2+ sites in the lattice were identified. The principal values of g- and A-tensors indicate that the symmetry of the electrostatic field around the Cu2+ ion is rhombic. Bonding parameters have been evaluated and the ground state wave function of Cu2+ ion is constructed. The ground state is found to be an admixure of |x2−y2〉 and |3z2−r2〉 orbitals. By correlating EPR and optical absorption spectra the crystal field parameters have been evaluated.