IMF2017

Ferroelectric nanocomposite materials have emerged as a modern research object for studying advanced properties suitable for nanotechnology applications due to the possibility of regulating their properties caused by the size effects. In this context, the development of nanotechnology led to the production of nano-sized silica SiO₂, which is widely used as a filler in these composites. With the high absorption ability of nanoparticles SiO₂ relating to moisture due to the presence of -ОН groups on their surface, the study of influence of humidity on electrophysical properties of SiO₂ can be considered as an urgent task and as a necessary step to understand properties of nanocomposite materials with the component of SiO₂ nanoparticles. The present work devoted to the study of influence of humidity on electrophysical properties of SiO₂ in a weak electric field (1 V/cm) at low frequencies in a temperature range from 15 °C to 112 °C. Samples SiO₂ were prepared from silica hydrosol with nanodispersed particles of ~ 6 nm by using the evaporation method. The obtained experimental results for SiO₂ samples in high-moistened regime showed high values of dielectric constant (up to 240 000) and a sharp increase in the values of dielectric loss with decreasing frequency at infra-low frequencies. The indicated anomalies can be associated to the reorientation of dipole moments of water molecules in nanochannels as well as the accumulation of volume charges at boundaries between SiO₂ nanoparticles due to Maxwell-Vagner polarization.