Role of PbO in EPR, optical properties and DC conductivity of vanadyl-doped alkali lead borate glasses

• Published in: Physica. B, Condensed matter Vol. 355; no. 1; pp. 44 - 53
• Main Authors: Gahlot, P.S., Seth, V.P., Agarwal, A., Sanghi, S., Chand, P., Goyal, D.R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2005; Elsevier
• Subjects: Borate glasses; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; DC conductivity; Electron paramagnetic resonance and relaxation; Electronic transport in condensed matter; EPR; Exact sciences and technology; Low-field transport and mobility; piezoresistance; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Vanadyl ion; 61.40; Borate glasses; DC conductivity; EPR; Optical properties; 66.30; 76.30; Vanadyl ion; 72.20; Vanadyl; Addition; Inorganic compounds; Electrical conductivity; Doping; Molecular interaction; 72.20 EPR; Energy gap; Molecular orbital method; Spin Hamiltonians; Chemical composition; Hyperfine interactions; Electron paramagnetic resonance; Activation energy
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2004.10.017

Glasses with composition xM 2O (0.30− x) PbO 0.70 B 2O 3 (M=Li, K) containing 2.0 mol% of V 2O 5 have been prepared in the range 0.00⩽ x⩽0.15 by normal melt quenching method. Electron paramagnetic resonance (EPR), optical properties and DC conductivity of these glasses have been studied. Spin Hamiltonian parameters (SHPs), dipolar hyperfine parameter, P and Fermi contact interaction parameter, K and molecular orbital coefficients ( α 2 and γ 2 ) have been calculated. In these glasses there is an increase in the tetragonality of the V 4+O 6 complex and the 3 d xy orbit expands with an increase in the M 2O:PbO ratio. Values of the theoretical optical basicity, Λ th, have also been reported. Optical band gap increases with decrease in PbO content. For x > 0.02 , the DC conductivity of these glasses increases and activation energy decreases.