An EPR and optical absorption study of VO2+ ions in di-ammonium hydrogen citrate [(NH4)(2)C6H6O7] single crystals
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, vol.69, no.2, pp.642-646, 2008 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 69 Issue: 2
- Publication Date: 2008
- Doi Number: 10.1016/j.saa.2007.05.015
- Journal Name: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.642-646
- Keywords: EPR, VO2+, metal ions, optical absorption, di-ammoniurn hydrogen citrate, DAHC, VANADYL ION, ESR-SPECTRA, GLASSES, CU2+, ACID
- Ondokuz Mayıs University Affiliated: Yes
Abstract
Single crystal and powder EPR studies of VO2+ doped di-ammonium hydrogen citrate [(NH4)(2)C6H6O7] 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 12,345 cm(-1). Spin Hamiltonian parameters and molecular orbital coefficients are calculated from the EPR and optical data, and results are discussed. (c) 2007 Published by Elsevier B.V.