The effect of water on permittivity properties of nanodielectrics exposed to the atmosphere

Relative dielectric constant and dissipation factor (tandelta) values as a function of frequency have been measured for a variety of water types. The effect of water absorption on the permittivity properties of crystalline powders or nanopowders when exposed to various humidity levels is also examined. Powdered materials were characterized by XRD and were calcite (CaCO
₃
), anatase, rutile (TiO
₂
), gamma and delta alumina (Al
₂
O
₃
). The change induced in the polarization of the powders by the applied dehydration procedures, i.e. high vacuum 10
^-6
mbar and calcination at temperatures up to 500degC, was investigated.