Electromagnetic interference shielding properties of sintered cement-based ceramics

Abstract

Cement-based ceramic pellets were prepared and their properties were studied for electromagnetic interference (EMI) shielding applications. The shielding materials were made of Portland cement with the addition of different concentrations of manganese oxide (MnO₂) up to 10 wt%. The pellets were sintered at 850 °C for 5 h and then polished prior to characterizations of density, porosity, microstructures, dielectric properties, and EMI shielding effectiveness (SE). Results show that the MnO₂–cement pellets have good dielectric properties, i.e. high dielectric constant (∼300) and low dielectric loss (<0 .3="" constant="" dielectric="" increased="" increasing="" mno="" sub="" the="" with="">2

content in the cement matrix. The SE values of the MnO₂–cements fluctuated between 2 dB and 9 dB in the frequency range of 8–13 GHz. The sample with 10 wt% MnO₂ additive had SE values of up to 9 dB. Most of the samples with high additive concentrations produced SE exceeding 7 dB.

Keywords

• A. Sintering;
• B. Composites;
• C. Dielectric properties;
• E. Functional applications;
• Electromagnetic interference shielding;
• Manganese oxide

Ceramics International

Volume 38, Issue 1, January 2012, Pages 671–678