Ionic conductivity, dielectric and optical properties of lithium lead borophosphate glasses combined with manganese ions

Multi-component transparent glasses of composition 20Li(2)O-20PbO-45B(2)O(3)-(15-x)P2O5-xMnO, with 0 <= x <= 3 mol% (x = 0, 0.2, 0.4, 0.6, 1, 2 and 3), were fabricated by the melt quenching technique. The amorphous nature of the samples was asserted by X-ray diffraction. FTIR analysis disclosed the bands due to Mn-O specific vibrations along with conventional borate and phosphate groups. EPR and optical absorption spectra were recorded at ambient temperature. The results demonstrated that manganese ions exist in Mn2+ and Mn3+ states and occupy octahedral sites in the glass network. Dielectric studies such as dielectric constant (epsilon'), loss (tan delta) and a.c. conductivity (sigma(ac)) in the frequency range 10(3)-10(6) Hz in the temperature range 30-300 degrees C were also carried out on these samples. These studies have revealed that the glasses exhibited semiconducting nature and such nature increases with increase in the concentration of MnO. (C) 2015 Elsevier B.V. All rights reserved.