Dielectric and electrical properties of a mullite/glass composite from a kaolinite clay/mica-rich kaolin waste mixture

Abstract A mullite/glass composite has been prepared by reactive sintering of a kaolinite clay/mica-rich kaolin waste mixture with 25 wt% waste. Phase composition, microstructure, dielectric and electrical properties of the composite fired at 1400 °C were evaluated by X-ray diffraction, scanning electron microscopy and impedance spectroscopy (between 25 and 600 °C in air). The microstructural characterization showed the attainment of dense samples composed of acicular (orthorhombic) mullite (47.6 wt%), glassy phase (50.1 wt%), and residual quartz (2.3 wt%). Electrical conductivity (1.9x10-8 S/cm at 300 °C), dielectric constant (6.7 at 1 MHz, 25 °C) and dielectric loss (0.024 at 1 MHz, 25 °C) results gave evidence that the mullite/glass composite is a promising low-cost material for commercial use in electronics-related applications.

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Bibliographic Details
Main Authors: Grilo,J. P. F., Alves,H. P. A., Araújo,A. J. M., Andrade,R. M., Dutra,R. P. S., Macedo,D. A.
Format: Digital revista
Language:English
Published: Associação Brasileira de Cerâmica 2019
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0366-69132019000100117
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