ESR and optical study of Cu2+ doped calcium malonate dihydrate

The ESR study of Cu2+ doped calcium malonate dihydrate has been done at room temperature. Four magnetically in-equivalent sites for Cu2+ have been observed. The spin-Hamiltonian parameters evaluated with the fitting of spectra to rhombic symmetry crystalline field are for Cu2+ site (I): gx = 2.0963 ± 0.0002, gy = 2.1316 ± 0.0002, gz = 2.4137 ± 0.0002, Ax = (32 ± 2) × 10−4 cm−1, Ay = (34 ± 2) × 10−4 cm−1, Az = (49 ± 2) × 10−4 cm−1, for site (II): gx = 2.0668 ± 0.0002, gy = 2.0800 ± 0.0002, gz = 2.3561 ± 0.0002, Ax = (34 ± 2) × 10−4 cm−1, Ay = (36 ± 2) × 10−4 cm−1, Az = (51 ± 2) × 10−4 cm−1, for site (III): gx = 2.0438 ± 0.0002, gy = 2.0623 ± 0.0002, gz = 2.2821 ± 0.0002, Ax = (34 ± 2) × 10−4 cm−1, Ay = (36 ± 2) × 10−4 cm−1, Az = (53 ± 2) × 10−4 cm−1, and for site (IV): gx = 2.0063 ± 0.0002, gy = 2.0241 ± 0.0002, gz = 2.2357 ± 0.0002, Ax = (35 ± 2) × 10−4 cm−1, Ay = (37 ± 2) × 10−4 cm−1, Az = (54 ± 2) × 10−4 cm−1. The ground state wave function of Cu2+ has also been determined. The g-anisotropy has been estimated and compared with the experimental value. Further with the help of optical study the nature of bonding of metal ion with different ligands in the complex has been discussed.