Effects of mixed-alkali oxides on structural, thermal, AC conductivity, dielectric and optical properties of xNa2O-(20-x)K2O-30V2O5-50TeO2 glasses / Siti Juliana Japari

Effects of mixed-alkali oxides on structural, thermal, AC conductivity, dielectric and optical properties of xNa2O-(20-x)K2O-30V2O5-50TeO2 glasses / Siti Juliana Japari

Tellurovanadate glasses containing sodium and potassium oxides with compositions xNa2O-(20-x)K2O-30V2O5-50TeO2 (x = 0-20 mol%) were prepared by melt-quenching method to investigate the effects of mixed-alkali oxide on structural, thermal, AC conductivity, dielectric and optical properties. Str...

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Main Author: Japari, Siti Juliana
Format: Thesis
Language:English
Published: 2020
Subjects:
Optics
Light
Online Access:https://ir.uitm.edu.my/id/eprint/60043/1/60043.pdf
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spelling my-uitm-ir.600432022-05-20T12:12:42Z Effects of mixed-alkali oxides on structural, thermal, AC conductivity, dielectric and optical properties of xNa2O-(20-x)K2O-30V2O5-50TeO2 glasses / Siti Juliana Japari 2020-04 Japari, Siti Juliana Optics. Light Tellurovanadate glasses containing sodium and potassium oxides with compositions xNa2O-(20-x)K2O-30V2O5-50TeO2 (x = 0-20 mol%) were prepared by melt-quenching method to investigate the effects of mixed-alkali oxide on structural, thermal, AC conductivity, dielectric and optical properties. Structural analysis revealed the presence of bridging oxygen (BO) and non-bridging oxygen (NBO). Thermal analysis results showed decrease value of glass transition temperature from 233 °C to minimum at 227 °C (x = 10 mol%) and then increased from 235 °C to 237 °C (x ≥ 10 mol%) as Na2O content increased. The variation of AC conductivity showed a non-linear behaviour with Na2O at temperature 383K, where increased from 7.15 10-10 Sm-1 to maximum value at 1.40 10-9 Sm-1 (x = 15 mol%) and shifted to 1.38 10-8 Sm -1 (x = 10 mol%) at temperature 463K. Meanwhile, dielectric constant showed increase in the frequency 0.01 Hz at 2.12 10-2 Fm-1 from to a maximum at 2.55 10-2 Fm-1 (x = 10 mol%) before decreasing value at 2.37 10-2 Fm-1 to 2.47 10-2 Fm-1 (x >10 mol%) at 383 K. The maximum in the value at x = 10 mol% coincided with the anomaly. Optical band gap showed initially decrease from 2.33 to 2.30 eV (x ≤ 10 mol%) and then increased from 2.31 to 2.39 eV for x >10 mol%, which is suggested to be related to the changes in concentration of non-bridging (NBO). Urbach energy behaves inversely with . In same region (x = 10 mol%), refractive index (n) also exhibited a maximum value at 2.77 which similar behaviour with the dielectric anomaly indicating that NBO is more polarizable on the properties. 2020-04 Thesis https://ir.uitm.edu.my/id/eprint/60043/ https://ir.uitm.edu.my/id/eprint/60043/1/60043.pdf text en public masters Universiti Teknologi MARA Faculty of Applied Sciences Yahya, Ahmad Kamal Hayati (Prof. Dr.)
institution Universiti Teknologi MARA
collection UiTM Institutional Repository
language English
advisor Yahya, Ahmad Kamal Hayati (Prof. Dr.)
topic Optics
Light
spellingShingle Optics
Light
Japari, Siti Juliana
Effects of mixed-alkali oxides on structural, thermal, AC conductivity, dielectric and optical properties of xNa2O-(20-x)K2O-30V2O5-50TeO2 glasses / Siti Juliana Japari
description Tellurovanadate glasses containing sodium and potassium oxides with compositions xNa2O-(20-x)K2O-30V2O5-50TeO2 (x = 0-20 mol%) were prepared by melt-quenching method to investigate the effects of mixed-alkali oxide on structural, thermal, AC conductivity, dielectric and optical properties. Structural analysis revealed the presence of bridging oxygen (BO) and non-bridging oxygen (NBO). Thermal analysis results showed decrease value of glass transition temperature from 233 °C to minimum at 227 °C (x = 10 mol%) and then increased from 235 °C to 237 °C (x ≥ 10 mol%) as Na2O content increased. The variation of AC conductivity showed a non-linear behaviour with Na2O at temperature 383K, where increased from 7.15 10-10 Sm-1 to maximum value at 1.40 10-9 Sm-1 (x = 15 mol%) and shifted to 1.38 10-8 Sm -1 (x = 10 mol%) at temperature 463K. Meanwhile, dielectric constant showed increase in the frequency 0.01 Hz at 2.12 10-2 Fm-1 from to a maximum at 2.55 10-2 Fm-1 (x = 10 mol%) before decreasing value at 2.37 10-2 Fm-1 to 2.47 10-2 Fm-1 (x >10 mol%) at 383 K. The maximum in the value at x = 10 mol% coincided with the anomaly. Optical band gap showed initially decrease from 2.33 to 2.30 eV (x ≤ 10 mol%) and then increased from 2.31 to 2.39 eV for x >10 mol%, which is suggested to be related to the changes in concentration of non-bridging (NBO). Urbach energy behaves inversely with . In same region (x = 10 mol%), refractive index (n) also exhibited a maximum value at 2.77 which similar behaviour with the dielectric anomaly indicating that NBO is more polarizable on the properties.
format Thesis
qualification_level Master's degree
author Japari, Siti Juliana
author_facet Japari, Siti Juliana
author_sort Japari, Siti Juliana
title Effects of mixed-alkali oxides on structural, thermal, AC conductivity, dielectric and optical properties of xNa2O-(20-x)K2O-30V2O5-50TeO2 glasses / Siti Juliana Japari
title_short Effects of mixed-alkali oxides on structural, thermal, AC conductivity, dielectric and optical properties of xNa2O-(20-x)K2O-30V2O5-50TeO2 glasses / Siti Juliana Japari
title_full Effects of mixed-alkali oxides on structural, thermal, AC conductivity, dielectric and optical properties of xNa2O-(20-x)K2O-30V2O5-50TeO2 glasses / Siti Juliana Japari
title_fullStr Effects of mixed-alkali oxides on structural, thermal, AC conductivity, dielectric and optical properties of xNa2O-(20-x)K2O-30V2O5-50TeO2 glasses / Siti Juliana Japari
title_full_unstemmed Effects of mixed-alkali oxides on structural, thermal, AC conductivity, dielectric and optical properties of xNa2O-(20-x)K2O-30V2O5-50TeO2 glasses / Siti Juliana Japari
title_sort effects of mixed-alkali oxides on structural, thermal, ac conductivity, dielectric and optical properties of xna2o-(20-x)k2o-30v2o5-50teo2 glasses / siti juliana japari
granting_institution Universiti Teknologi MARA
granting_department Faculty of Applied Sciences
publishDate 2020
url https://ir.uitm.edu.my/id/eprint/60043/1/60043.pdf
_version_ 1783735074247671808

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