Microstructures and dielectric relaxation behaviors of pure and tellurium doped CaCu 3Ti 4O 12 ceramics prepared via vibro-milling method

• Main Authors: Makcharoen W., Tunkasiri T.
• Format: Article
• Language: English
• Published: 2014
• Online Access: http://www.scopus.com/inward/record.url?eid=2-s2.0-84867750791&partnerID=40&md5=b54755dac1fdfcf6a3f0a363928d833a; http://cmuir.cmu.ac.th/handle/6653943832/6912
• Institution: Chiang Mai University

In this work, we have reported microstructures and the dielectric properties of CaCu 3Ti 4O 12 (CCTO) ceramics doped with different proportions of TeO 2 dopant (mol%, x=0, 0.5%, 1.0%, 2.0%). The pure and tellurium doping CCTO ceramics were prepared by a conventional solid-state reaction method and the effects of TeO 2 doping on the electrical properties and microstructures of these ceramics were investigated. XRD analysis confirmed the formation of single-phase material in samples. Scanning electron microscopy (SEM) is used in the micro structural studies of the specimens, which showed that TeO 2 doping can reduce the mean grain size and increasing size of an abnormal grain growth. Lattice parameter increases slightly with tellurium doping in CCTO, the dielectric constant reached a value as high as 18,000 (at 1 kHz) at a tellurium-doping concentration of 2.0 mol% and showed temperature stability at high frequency. The loss tangent of Te-doped CCTO ceramics was less than 0.05 at 1 kHz region below 105 °C. The loss tangent properties could be interpreted by the internal barrier layer capacitor model and the impedance measurement data. Crown Copyright © 2012.