EPR Study of VO2+ Doped Diammonium Tricadmium Tetrakis (Sulfate) Pentahydrate [(NH4)2Cd3(SO4)4 ∙ 5H2O] Single Crystals

Electron paramagnetic resonance (EPR) studies are carried out on vanadyl (VO2+) ions in diammonium tricadmium tetrakis (sulfate) pentahydrate single crystals at room temperature. The EPR spectra of a single crystal exhibit resonance signals characteristic to VO2+ ions. The analysis of EPR spectra indicates that the VO2+ ions in single crystals show two magnetically inequivalent VO2+ sites in distinct orientations occupying substitutional positions in the lattice and showing very high angular dependence. They form in octahedral coordination with tetragonal compression with C4v symmetry. The spin Hamiltonian parameters are determined, and these parameters have been used to estimate the bonding coefficients of the VO2+ ion in a diammonium tricadmium tetrakis (sulfate) pentahydrate lattice. The parallel and perpendicular components of axially symmetric g and hyperfine (A) tensors are evaluated and the results are discussed and compared with previous reports.