Electrical and spectroscopic properties of Fe2O3 doped Na2SO4–BaO–P2O5 glass system

Dielectric dispersion and ac conduction phenomena of Li2O−Sb2O3−PbO−GeO2:Cr2O3 glass system

“…Such produced defects create easy pathways for the migration of charge carriers that would enhance the space charge polarization and caused an increase of ε 0 (ω) with temperature [58][59][60]. At higher frequency, ε 0 (ω), for all the studied samples approached a near constant value, ε 0 1 ðωÞ, which resulted from rapid polarization processes occurring in the glasses under applied field [61]. At these frequencies the charge carriers would not be able to rotate sufficiently rapidly, so their oscillation would begin to lay behind this field and lead to a decrease of dielectric permittivity, ε 0 (ω).…”

Dielectric and Spectroscopic properties of CuO doped multi-component Li2OPbOB2O3SiO2Bi2O3Al2O3 glass system

“…In other words, as the concentration of Al 2 O 3 is raised beyond 3.0 mol%, there is a growing presence of octahedral aluminum ions in the glass network (as is evidenced from the spectroscopic studies); these ions, as stated earlier, similar to Li + and Cu 2+ ions, disrupt the glass network by creating dangling bonds and non-bridging ions. The defects thus produced create easy path ways for the migration of charge carriers that would build up space charge polarization leading to the increase in the dielectric parameters as observed [34,35].The low value of dielectric constant of titled glass samples mixed up to 3.0 mol% of Al 2 O 3 supports the view point that in these the concentration range Al 3+ ions mainly occupy tetrahedral positions and increase the rigidity of the glass network. The variation of dielectric loss with temperature of CuO doped Li 2 O\ PbO\B 2 O 3 \SiO 2 \Bi 2 O 3 \Al 2 O 3 glasses exhibited the relaxation character.…”

Structural features of iron‐phosphate glass

“…These M€ ossbauer spectra are typical for Fe 2+ and Fe 3+ ions in octahedral coordination. 12,14 It is found that some of the Fe 3+ ions in the starting batch are reduced to Fe 2+ ions, after melting at 1200°C for 1 hour in air, as determined from the M€ ossbauer spectrum. In according to the results the fractions of Fe 2+ and Fe 3+ were determined to be 18% and 82%, respectively.…”

“…12 Further, it is also quite likely that the tetrahedral iron that strengthens the glass network with PO4 structural units. 14 Although demonstrated that the chemical durability in aqueous solution of the F40 glass was independent of the relative concentration of Fe 2+ or Fe 3+ ions, 5,15 the reasons for increased chemical durability are still not entirely understood. However, the expected increased hydration resistance of the P-O-Fe links being cited as a possible reason.…”