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

•Li2O–PbO–B2O3–P2O5: MnO glasses were developed by melt quenching method.•Spectroscopic and dielectric properties of MnO doped glasses were investigated.•EPR spectra confirmed the existence of Mn2+ and Mn3+ ions in the glass matrix.•Glass mixed with 3 mol% of MnO exhibited the highest conductivity.•The semiconducting nature of the glasses rises gradually with the hike in MnO.

Multi–component transparent glasses of composition 20Li2O–20PbO–45B2O3–(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 (ε′), loss (tanδ) and a.c. conductivity (σac) in the frequency range 103–106 Hz in the temperature range 30–300 °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.

Graphical abstractLithium lead borophosphate glasses were synthesized by melt quenching technique. The X–ray diffraction pattern asserted the amorphous nature of the glasses. The FTIR studies showed the conversion of some of BO4 units into BO3 units due to the increasing concentration of modifying manganese ions in the glass network. The optical absorption and EPR spectra manifested the presence of Mn2+ and Mn3+ ions in octahedral positions at higher concentrations of MnO. The increase in the values of ε′, tanδ and σac with the increase in concentration of MnO is attributed to space charge polarization.Figure optionsDownload full-size imageDownload as PowerPoint slide