High-Frequency Dielectric Properties of Nanocomposite and Ceramic Titanates

A set of ferroelectric and related titanate ceramics and nanocomposites were prepared and their dielectric and electromagnetic properties were studied in a broad frequency range, including microwave, millimeter-wave and THz frequencies. Dielectric and conductivity spectra of the opal-matrix nanocomposites were typical for conductor-dielectric composites and could be described by Cole-Cole relaxations and Drude conductivity. The highest values of microwave dielectric permittivity, losses and conductivity were observed in the composite with Pr₂Ti₂O₇ nanoparticles. Absorption properties of ceramic and some composite titanates were measured and estimated in the microwave range. Some of the studied compositions were found to be interesting for development of microwave absorbing or shielding materials.