title: Dinuclear manganese centers in the manganese-lead-tellurate glasses.
abstract: FTIR, UV-VIS and EPR spectra of manganese doped lead-tellurate glasses with composition xMnO·(100-x)[4TeO2·PbO2] where x=0, 1, 5, 10, 20, 30, 40mol% have been studied. The FTIR spectra show the formation of the Mn-O-Pb and Mn-O-Te bridging bonds by increasing of MnO concentration. The UV-VIS spectra show the Mn(+3) species exhibit pronounced absorption, which masks the Mn(+2) spin-forbidden absorption bands when Mn(+2) ions are in high concentrations in these glasses. The EPR spectra exhibit resonance signals characteristic of Mn(+2) ions. The resonance signal located at g≈2 is due to Mn(+2) ions in an environment close to octahedral symmetry, whereas the resonance at g≈4.3 and 3.3 are attributed to the rhombic surroundings of the Mn(+2) ions. The increase in the MnO content gives rise to absorption at g≈2.4 and the paramagnetic ions are involved in dinuclear manganese centers.
authors.affiliation: Department of Physics, Technical University of Cluj-Napoca, 400641, Romania. Simona.Rada@phys.utcluj.ro
authors.forename: S
authors.initials: S
authors.lastname: Rada
authors.forename: A
authors.initials: A
authors.lastname: Dehelean
authors.forename: M
authors.initials: M
authors.lastname: Culea
authors.forename: E
authors.initials: E
authors.lastname: Culea
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005898:Glass / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D013053:Spectrophotometry; D017550:Spectroscopy, Fourier Transform Infrared; D013691:Tellurium / Q000737:chemistry*
chemical_list: D007854:Lead; D008345:Manganese; C026660:tellurous acid; D013691:Tellurium