Influence of Ga3+ ions on spectroscopic and dielectric features of multi component lithium lead boro bismuth silicate glasses doped with manganese ions

• A series of Li2O–PbO–B2O3–SiO2–Bi2O3–MnO:Ga2O3 glasses have been synthesized.
• A variety of spectroscopic and dielectric properties have been investigated.
• Analysis of the results indicated that glasses with below 3.0 mol% Ga2O3 are good conducting materials.

Multi-component glasses of the chemical composition 19.5Li2O–20PbO–20B2O3–30SiO–(10 − x)Bi2O3–0.5MnO:xGa2O3 with 0 ≤ x ≤ 5.0 have been synthesized. Spectroscopic (optical absorption, IR, Raman and ESR) and dielectric properties were investigated. Optical absorption and ESR spectral studies have indicated that managanese ions do exist in Mn3+ state in addition to Mn2+ state in the samples containing low concentration of Ga2O3. The IR and Raman studies indicated increasing degree of disorder in the glass network with the concentration of Ga2O3 up to 3.0 mol%. The dielectric constant, loss and ac conductivity are observed to increase with the concentration of Ga2O3 up to 3.0 mol%. The quantitative analysis of the results of dielectric properties has indicated an increase in the insulating strength of the glasses as the concentration of Ga2O3 is raised beyond 3.0 mol%. This has been attributed to adaption of gallium ions from octahedral to tetrahedral coordination.

The plots between ɛ″(ω)ω vs. ɛ′(ω) and ɛ″(ω)/ω vs. ɛ′(ω) yield straight lines with slope 1/τ and τ, respectively. Considerable deviation from the straight line is observed in the high frequency region. Such deviation suggests spreading of relaxation times and this is attributed to the presence of multiple type of dipoles in the glass matrix. Variation of the parameters ωɛ″(ω) and ɛ″(ω)/ω with ɛ′(ω) of glass Li2O–PbO–B2O3–SiO2–Bi2O3–MnO multi-component glasses mixed with 2.0 mol% of Ga2O3 measured at 373 K.Figure optionsDownload as PowerPoint slide