Impact of high NiO content on the structural, optical, and dielectric properties of calcium lithium silicate glasses

Abstract

Glasses with the composition (11.5 − ×) CaO − 23.5Li2O − 65SiO2: × NiO mol. % (0 $$\le \times \leq$$ ≤ × ≤ 11.5) were synthesized by melt-quenching method. And a number of physical parameters have been established. The refractive index and energy gap were also used to estimate the metallization criterion, where these glasses have shown values fallings between high (insulators) and low (metals), indicating that they are semiconductors. The XRD pattern shows the amorphous nature of investigated glasses. A number of spectroscopic analyses of the studied glasses were performed, in relation to NiO content, including Fourier transform infrared (FTIR) and UV–Visible diffuse reflectance spectroscopy (DRS). Due to compositional changes, FTIR measurements have revealed structural changes in the glass network. Furthermore, with increasing NiO content, the asymmetrical bands of silicate units increase. The creation of Ni–O–Si bonds in the silicate matrix has been attributed to the introducing heavier Ni+2 as [NiO4]2− tetrahedral species in substitution of the lighter silicon ion in the [SiO4]4− network, but it could also operate as a network modifier in glass materials. The Ni2+ ion may have behaved as a network intermediary, causing more compact structure. The mechanism of charge transfer in the glass compositions under investigation is studied using broadband dielectric spectroscopy. For the first time, the relationship between the hopping time of free ions and dc conductivity is illustrated. All of the glasses under investigation have the same charge transport mechanism. The results suggest the semiconducting nature of these glasses.

Tailoring ZnO/CoFe2O4 nanocomposites: structure, optical, dielectric and magnetic study

“…However the conductivity contribution at the lower frequency region tends to be a clear peak in the modulus representation instead of the linear relation in the dielectric spectrum, the peak attributed to the interfacial polarization became more clear and sharp than that in the dielectric plot. One can conclude that The Interfacial (space charge) polarization separated remarkably in the modulus presentation from the conductivity contribution peak as stated very recently in the case of some calcium lithium silicate glasses [45]. As the temperature increases to 150 C, figure 11 shows a systematic decrease of the dc-conductivity with increasing the ferrite concentration.…”

“…The frequency dependence of permittivity, ε′, shows high values at a lower frequency region and decreases gradually with increasing frequency, and remains constant at higher frequencies. This has now become a typical characteristic behavior of dielectric materials [45][46][47]. The permittivity is higher at the low range of frequency due to the correlation between space charge or interfacial polarization (usually called Maxwell Wagner Siller, MWS-Polarization) on one hand and the charge Carriers' transport on the other hand.…”

Gamma induced changes in Makrofol/CdSe nanocomposite films

“…The tiny size of the NPs gives them a much larger surface area to volume ratio which is an important feature for reactivity, that is, the rate at which the chemical reaction will proceed, because more surfaces are vacant to react and assist chemical processes. [36] Accordingly, the atomic volume full of NPs reduces, hence its density and absorbance increase. [37] In other words, the increase in absorbance with increasing γ dosage denotes the absorption of the incident photon energy by the NCP intermediate atoms.…”

Effect of high-energy radiation on the electrical and optical characteristics of bioactive glasses

“…However, even though calcium, phosphate, strontium, and borate ions affect the electrochemical properties, electrical characteristics have significant effects on metabolic properties 10 especially the bonding properties with tissues, the polarity, dielectric, resistivity, and optical effects have attracted more interest to study these properties for hydroxyapatites. Investigations on electrical properties [11][12][13][14][15][16][17] indicate that electrical behaviors of calcinated materials create several phenomena, which control the electrical properties. Both Ibrahim et al 11 and Singh et al 12 have discussed the detailed mechanisms in bone growth for materials systems and electrical characteristics.…”

“…Investigations on electrical properties [11][12][13][14][15][16][17] indicate that electrical behaviors of calcinated materials create several phenomena, which control the electrical properties. Both Ibrahim et al 11 and Singh et al 12 have discussed the detailed mechanisms in bone growth for materials systems and electrical characteristics. They explained the charge transfer in the glass systems using broadband dielectric values.…”