Single crystal EPR and optical absorption studies of Cu 2+ ion in l-arginine sulphophosphate monohydrate—a nonlinear optical crystal

Abstract

The EPR spectra of Cu 2+ ion in l-arginine sulphophosphate monohydrate (LASP), a nonlinear optical material (NLO) have been studied at room temperature. Two magnetically inequivalent interstitial Cu 2+ sites in the lattice were identified. The principal values of g- and A-tensors indicate that the symmetry of the electrostatic field around the Cu 2+ ion is rhombic. Bonding parameters have been evaluated and the ground state wave function of Cu 2+ ion is constructed. The ground state is found to be an admixure of | x 2 − y 2 〉 and | 3 z 2 − r 2 〉 orbitals. By correlating EPR and optical absorption spectra the crystal field parameters have been evaluated.