Electron Paramagnetic Resonance and Optical Absorption of VO²⁺ Doped Bis (glycinato) Mg (II) Monohydrate Single Crystals

We investigate the electron paramagnetic resonance (EPR) of VO²⁺ ions in bis (glycinato) Mg (II) monohydrate single crystals at room temperature. Detailed EPR analysis indicates the presence of only one VO²⁺ site. The vanadyl complexes are found to take up the substitutional position. The angular variation of the EPR spectra in three planes a*b, bc and ca* are used to determine principal g and A tensors. The values of spin Hamiltonian parameters are g_x= 2.1447× 10^-4, g_y= 1.9974×10^-4, g_z= 1.9131×10^-4, A_x= 49×10^-4, A_y= 60×10^-4, A_z= 82×10^-4 cm^-1. The optical absorption study is also carried out at room temperature and absorption bands are assigned to various transitions. The theoretical band positions are obtained using energy expressions and a good agreement is found with the experimental data. By correlating EPR and optical data, different molecular orbital coefficients are evaluated and the nature of bonding in the crystal is discussed.