The Optical Absorption and Electron Paramagnetic Resonance of Cu2+ Incorporated Dicalcium Lead Propionate

Abstract

Following γ-ray exposure, a room-temperature study of electron paramagnetic resonance (EPR) is conducted on Cu²⁺-doped dicalcium lead propionate (DCLP), Ca₂Pb(C₂H₅COO)₆. Cu²⁺ is found at four magnetically equivalent sites replacing Ca²⁺. EPR spectra are fitted to a rhombic symmetry Hamiltonian in order to determine the spin Hamiltonian parameters. The determined parameters are g_x = 2.0245 ± 0.0002, g_y = 2.1024 ± 0.0002, g_z = 2.3476 ± 0.0002, A_x = (56 ± 2) × 10⁻⁴ cm⁻¹, A_y = (78 ± 2) × 10⁻⁴ cm⁻¹, and A_z = (98 ± 2) × 10⁻⁴ cm⁻¹. The experimental value of g-anisotropy is compared with the evaluated one. The wavefunction for the ground state is determined to be 0.999|x² − y²> − 0.004|3z² − r²>. The complex's bonding nature is determined with the aid of an optical study. The optical transitions d_x2−y2 → d_xy(²B_1g → ²B_2g), d_x2−y2 → d_xz,yz(²B_1g → ²E_g), and d_x2−y2 → d_3z2-r2(²B_1g → ²A_1g) are observed at 12,121, 18,691, and 25,316 cm⁻¹, respectively. The molecular orbital coefficients α₀², β₁², β₀², and β′² and Fermi contact term K for Cu²⁺-doped DCLP are found as 0.63, 1.00, 1.00, 0.40, and 0.44, respectively.