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DC and Thermal Conductivity of Lithium Zinc Phosphate Glasses

Solid State Phenomena

October 2017
268:198-204

DOI:10.4028/www.scientific.net/SSP.268.198

Authors:

Md Rahim Sahar

University of Technology Malaysia

Azman Kasim

MARA University of Technology

Show all 5 authorsHide

The phosphate glasses, with composition (60-x)P2O5-25ZnO-(15+x)Li2O where 0.0 ≤ x ≤ 5.0 mol% are prepared by conventional melt quenching method. The amorphous nature of the glass is determined by X-Ray Diffraction (XRD). The physical properties are measured in term of their density and molar volume. Glass density is found to increase from 2.700 to 2.785 g cm⁻³ whereas molar volume is found to decrease from 40.735 to 37.488 cm³ mol⁻¹ with respect to Li2O content. The DC measurements are done by using four point probes and the activation energies are determined. Arrhenius plot shows straight line behavior as observed that confirmed the conductivity increased with Li2O content. The activation energy is found to decreases from 0.75 to 0.08 eV as Li2O content is increased in the temperature range from 310 to 420 K. Measurements of the thermal conductivity using Lee’s disc apparatus have been made. It is observed that the maximum and minimum thermal conductivity are 0.2679 and 0.2168 W m⁻¹ K-1 respectively.

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DC and Thermal Conductivity of Lithium Zinc Phosphate Glasses

A.M. Hilman1,a, E.S. Sazali2,b*, M.R. Sahar2,c, K. Azman1,d, Y. Norihan1,e

1Faculty of Applied Sciences, Universiti Teknologi MARA Pahang, 26400 Jengka, Pahang,

Malaysia

2Advanced Optical Material Research Group, Department of Physics, Faculty of Science,

Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia

ahilmanmanang@gmail.com, bezzasyuhada@utm.my, cmrahim057@gmail.com,

dazman615@pahang.uitm.edu.my, enorihan@pahang.uitm.edu.my

*Corresponding author: ezzasyuhada@utm.my

Keywords: phosphate glass, density, activation energy, DC conductivity, thermal conductivity

Abstract. The phosphate glasses, with composition (60-x)P2O5-25ZnO-(15+x)Li2O where 0.0 ≤ x ≤

5.0 mol% are prepared by conventional melt quenching method. The amorphous nature of the glass

is determined by X-Ray Diffraction (XRD). The physical properties are measured in term of their

density and molar volume. Glass density is found to increase from 2.700 to 2.785 g cm-3 whereas

molar volume is found to decrease from 40.735 to 37.488 cm3 mol-1 with respect to Li2O content.

The DC measurements are done by using four point probes and the activation energies are

determined. Arrhenius plot shows straight line behavior as observed that confirmed the conductivity

increased with Li2O content. The activation energy is found to decreases from 0.75 to 0.08 eV as

Li2O content is increased in the temperature range from 310 to 420 K. Measurements of the thermal

conductivity using Lee’s disc apparatus have been made. It is observed that the maximum and

minimum thermal conductivity are 0.2679 and 0.2168 W m-1 K-1 respectively.

Introduction

The phosphate glasses are crucial and change to challenging in development due to several

interesting properties such as lower melting point compared to silica based glasses and have high

thermal expansion coefficients [1]. However, phosphate glasses are limited in utilization due to its

hygroscopic properties in nature and have a lower glass transition temperature [2]. According to the

glass composition, the consequences of modifier ions contents with oxides in phosphate glasses can

lower the melting temperature of a specific composition of the phosphate glass systems [3].

Furthermore, an addition of alkali ions into glasses system result in high electrical conductivity; due

to the moving ions that carrying charges [4,5].

In this work, the study of density, DC conductivity, and thermal conductivity of P2O5-ZnO-

Li2O glasses with respect to Li2O content are carried out. Introduction of Li2O in glass system

contributes the alkali effect from its small atomic size and high ionic mobility [6], hence the

variation of activation energy would be identified through the Arrhenius trend.

Experimental Method

The phosphate glasses are prepared by using melt-quenching method. The glass

compositions of (60-x)P2O5-25ZnO-(15+x)Li2O are listed in Table 1 with (0.0 ≤ x ≤ 5.0 mol%). All

the starting materials, P2O5 (98.0%), ZnO (99.0%) and Li2CO3 (99.0%) which in powder form are

well mixed in alumina crucible before being placed into furnace at 900 °C for 30 minutes for

melting process. After the batch is completely melted, the molten it is poured onto steel mould and

annealed at 300 °C for 3 1/2 hours to reduce the mechanical stress. Then, the glass sample is

allowed to cool down to room temperature gradually.

Solid State Phenomena Submitted: 2016-10-21

ISSN: 1662-9779, Vol. 268, pp 198-204 Revised: 2017-07-05

doi:10.4028/www.scientific.net/SSP.268.198 Accepted: 2017-07-06

Tech Publications Ltd, www.scientific.net. (Research Gate for subscription journals-11/02/24,23:20:57)

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DC and Thermal Conductivity of Lithium Zinc Phosphate Glasses

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