Structural, Optical and Dielectric Properties of Tellurite Borate Glasses Doped with Cerium Oxide

• Published in: Journal of inorganic and organometallic polymers and materials 2023-08, Vol.33 (8), p.2319-2330
• Main Authors: Ibrahim, Samia E., El-Mallawany, R., Abouhaswa, A. S.
• Format: Article
• Language: English
• Subjects: Bismuth oxides; Bismuth trioxide; Boron oxides; Cerium oxides; Chemistry; Chemistry and Materials Science; Dielectric properties; Electrical resistivity; Energy gap; Frequency ranges; Glass; Inorganic Chemistry; Lithium oxides; Molar volume; Optical properties; Organic Chemistry; Polymer Sciences; Raman spectroscopy; Room temperature; Spectrum analysis; Substitutes; Tellurium; Tellurium dioxide; X-ray diffraction
• ISSN: 1574-1443; 1574-1451
• DOI: 10.1007/s10904-023-02682-0

Synthesis of tellurite borate (35-x) TeO 2  + 35 B 2 O 3  + 20 Bi 2 O 3  + 10 Li 2 O + x CeO 2 and x = 0, 0.5, 1.5, 3 mol% glasses have been achieved by using the melt quenching technique. Density, X-ray diffraction (XRD), Raman spectroscopy measurements and UV–Vis analysis were measured. Dielectric measurements were recorded in the frequency range of 100 Hz–100 kHz at room temperature. XRD patterns of all the investigated glass samples doped with CeO 2 are completely amorphous. Densities of the prepared glasses increased from 4.80 to 4.89 g/cm 3 and molar volumes decreased from 36.74 to 36.14 cm 3 /mole. Raman spectroscopy reveals that the Raman intensity increases with increasing substitution of CeO 2 by TeO 2 . UV–Vis analysis reveals that a higher CeO 2 substitution ratio increased the absorbance and optical properties of produced glass samples. The CeO 2 content of tellurium borate glass samples were found to affect all of the optical characteristics. With increasing CeO 2 concentration, the optical energy gap decreases ( E g opt ) from 2.77 to 1.96 eV for direct allowed transitions and from 2.45 to 1.82 eV for indirect allowed transitions. It has also been studied how electrical conductivity and dielectric properties change with frequency and composition. Values ε′, ε″ and σ ac of sample with x = 0 are greater than those values of with x = 3. The variation of the imaginary part of the electric modulus ( M″ ) versus frequency (F) plot curve is asymmetric of non-Lorentzian type. A shift of the frequency peak towards the higher frequency region was observed by increasing CeO 2 mol%.