A Comparative Study on the Dielectric Properties of Lanthanum Copper Titanium Dioxide Ceramic

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Mechanics, Materials Science & Engineering, July 2017 – ISSN 2412-5954

A Comparative Study on the Dielectric Properties of Lanthanum Copper Titanium Dioxide (La2/3Cu3Ti4O12) Ceramic with Conventional and Microwave Sintering Routes 1

Surya Mallick1, Pawan Kumar2, M. Malathi1, a 1 – Condensed Matter Research Laboratory, Department of Physics, School of Advance Sciences, VIT University, Vellore, Tamilnadu, India 2 – National Institute of Technology, Rourkela, Odisha, India a –mmalathi@vit.ac.in DOI 10.2412/mmse.6.46.507 provided by Seo4U.link

Keywords: microwave, conventional, dielectric, ceramics.

ABSTRACT. Lanthanum Copper Titanium Dioxide (La2/3Cu3Ti4O12, LCTO) precursor powders were synthesized by a cost effective solid-state reaction. The material is sintered at two different techniques one is conventional and other one is microwave. The microstructure and impedance characteristics were found to be strongly dependent on the sintering conditions. The sintering has been done at 1, 000oC for 4 thin conventional method and for 20, 40and 60 min in microwave method to compare the effects of two different sintering processes. X-ray powder diffraction study (XRD) analysis, dielectric constant, dielectric loss and Scanning Electron Microscopy (SEM) results are observed. Structural properties and phase formation was confirmed through XRD, this confirms Perovskite cubic structure of LCTO ceramics. Density of the samples determined using Archimedes principle with water as liquid medium. SEM micrographs are taken and results are being compared. Dielectric constant was investigated for different frequency values (1 kHz, 10 kHz, 100 kHz, 1 MHz) with temperature and the effective dielectric constant and loss as a function of frequency has been studied at room temperature. Dielectric constant of microwave-sintered sample was found to be higher compared to the conventional sintered sample at room temperature.

Introduction. Giant dielectric materials have become increasingly important due to the strong technological needs for the further reduction of dimensional size and the enhancement of performance in capacitance-based components like capacitors. In recent years a series of Perovskyte- related structure material, ACu3Ti4O12 (A= Ca1, La2/32, Y2/33, Na1/2Bi1/24, Na1/2La1/25) has been extremely investigated because of its giant dielectric constant accompanied by low dielectric loss at room temperature.La2/3Cu3Ti4O12 (LCTO)is a member of the ACu3Ti4O12 family but so far there are limited literatures reporting LCTO ceramics out of them most studies are focused on preparation, microstructure and dielectric properties of LCTO ceramics[1-3].LCTO ceramics can be fabricated by a conventional solid state reaction [4]. However, the solid-state reaction has some disadvantages such as long processing time, low purity and inhomogeneous grain size, which results in poor dielectric properties. In general, the improvement of the fabrication methods is an effective way to improve electrical characteristics of the ceramics. There are many alternative methods have been used to prepare electronic ceramics which includes Sol-gel method, hydrothermal synthesis, combustion route, spark plasma sintering , hot pressing, out of which Sol-gel method have been attempted to prepare LCTO ceramics[1, 4]. However, these methods are complex and expensive which makes it difficult in industrial application. Microwave sintering for electronic ceramics is superior to conventional sintering owing to its unique characteristics, such as rapid heating, enhanced densification rate and improved microstructure. Microwave heating differs significantly from 1

© 2017 The Authors. Published by Magnolithe GmbH. This is an open access article under the CC BY-NC-ND license http://creativecommons.org/licenses/by-nc-nd/4.0/

MMSE Journal. Open Access www.mmse.xyz


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