9.355 GHz complex permittivity of water from 1 degrees C to 90 degrees C

Abstract

This paper reports the results of a systematic study of the 9.355 GHz complex permittivity of double-distilled, deionized water over the temperature interval from 1 degrees C to 90 degrees C in approximately 2 degrees C steps. A precision of approximately 0.03% and an accuracy of approximately 0.1% were achieved for both the permittivity epsilon ' and the dielectric loss epsilon ". It shows that the values of the thermodynamic parameters entropy ( Delta S), enthalpy ( Delta H), and free energy ( Delta F) of activation are temperature dependent, contrary to previous reports. The temperature dependence of the relaxation time in this temperature interval is in good agreement with that reported in the literature. The values of the thermodynamic functions, calculated using the various pairs of alpha and epsilon infinity values reported in the literature, agree within 1 sigma over most of the measurement temperature interval.