JOURNAL OF ADVANCES IN SCIENCE, ENGINEERING AND TECHNOLOGY

Vol.1, Issue.1,  Jan-Mar 2025

Standard Journal Issues

 

Ionic Conductivity of (1-x)Na₀.₅Cd₀.₅NO₃ : xZrO₂ Electrolyte System

P. Sivaprasad1 and Y.Vijayakumar2   

1Research Institute of Physics, Indgiants, Hyderabad, Telangana, India

2Department of Physics, Anurag University, Hyderabad, Telangana, India

 

Abstract

 

In this study, zirconia (ZrO₂) nanoparticles with sizes below 100 nm were incorporated into a Na₀.₅Al₀.₅NO₃ matrix through mechanical milling for one hour using acetone as the medium. The process was carried out with varying mole percentages (m%) of ZrO₂. The resulting composite powders were compacted into pellets by applying a pressure of 5 tons/cm² and then sintered at 250 °C for 20 hours. These pellets were analyzed for their direct current (DC) ionic conductivity over a temperature range starting from room temperature up to the melting point. An increase in ionic conductivity was observed with rising ZrO₂ content, reaching a notable threshold at 15 m/o. The maximum conductivity improvement, particularly in the extrinsic conduction region, was found to be 1–2 orders of magnitude higher than that of the undoped host material. Characterization techniques including X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) were employed to investigate the structure and morphology of the composites. XRD and DSC results confirmed the absence of a solid solution between the host matrix and the ZrO₂ particles. The observed enhancement in conductivity is attributed to the formation of space charge layers and increased grain boundary density, which likely elevate the defect concentration within the host material. Correspondingly, the activation energy for conduction decreased up to the 15 m% threshold, after which it began to rise with further ZrO₂ addition. At higher ZrO₂ concentrations, the reduction in conductivity improvement is believed to be due to a blocking effect, where excessive ZrO₂ particles hinder the interface interactions between the host and the dispersed phase.

 

Key words: Solid-State ElectrolytesIonic Conductivity,Composite Electrolyte System, Zirconia (ZrO₂) Dispersion, Space Charge Effect

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