Structural, Thermal and Dielectric Properties of Low Dielectric Permittivity Cordierite-Mullite-Glass Substrates at Terahertz Frequencies.

Glass-ceramic composites containing cordierite, mullite, SiO glass and SiO-BO-AlO-BaO-ZrO glass were fabricated in a process comprising solid state synthesis, milling, pressing and sintering. Thermal behavior, microstructure, composition and dielectric properties in the Hz-MHz, GHz and THz ranges were examined using a heating microscope, differential thermal analysis, thermogravimetry, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction analysis, impedance spectroscopy, transmission method and time domain spectroscopy (TDS). The obtained substrates exhibited a low dielectric permittivity of 4.