title: An EPR and optical absorption study of VO2+ ions in di-ammonium hydrogen citrate [(NH4)2C6H6O7] single crystals.
abstract: Single crystal and powder EPR studies of VO2+ doped di-ammonium hydrogen citrate [(NH4)2C6H6O7] are carried out at room temperature. The angular variation of the EPR spectra show three different VO2+ complexes that are located in different chemical environment, and each environment contains two magnetically inequivalent VO2+ sites in distinct orientations occupying substitutional positions in the lattice. Crystalline field around the VO2+ ion is nearly axial. The optical absorption spectrum shows two bands centred at 16,949 and 12,345cm(-1). Spin Hamiltonian parameters and molecular orbital coefficients are calculated from the EPR and optical data, and results are discussed.
authors.affiliation: Ondokuz Mayis University, Faculty of Art and Sciences, Department of Physics, 55139 Samsun, Turkey. bbulut@omu.edu.tr
authors.forename: Bünyamin
authors.initials: B
authors.lastname: Karabulut
authors.forename: Ayşe
authors.initials: A
authors.lastname: Tufan
mesh_terms: D000042:Absorption; D002412:Cations / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry*; D003460:Crystallization; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006859:Hydrogen / Q000737:chemistry*; D015394:Molecular Structure; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D017968:Vanadium Compounds / Q000737:chemistry*
chemical_list: D002412:Cations; D000644:Quaternary Ammonium Compounds; D017968:Vanadium Compounds; D019343:Citric Acid; C481046:ammonium citrate; D006859:Hydrogen