Cold sintering of quartz ceramics and their peculiar effective properties

In the present paper, we demonstrate a densification of quartz by cold sintering and investigate the effect of various parameters (temperature, pressure, dwell time and content of the liquid phase) on the final density. Thermal conductivity and shear modulus are determined based on the measurement of thermal diffusivity and transversal sound velocity, respectively. The measured values are very low compared to existing predictions, thus suggesting a presence of microcracks/pores at grain boundaries. In some cases, a weak temperature dependance of thermal conductivity was observed and points to a presence of amorphous phase and/or crystallographic defects.