Paraelectric Response of Water in the Range 0-100°C

• Published in: Ferroelectrics Vol. 466; no. 1; pp. 166 - 180
• Main Authors: del Valle, J. C., Aragó, C., Marqués, M. I., Gonzalo, J. A.
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 04.07.2014; Taylor & Francis Ltd
• Subjects: dielectric constant; Dielectric properties; ferroelectric transition; ferroelectricity; Ferroelectrics; Molecules; paraelectricity; Physical properties; polarity; Temperature effects; Water
• ISSN: 0015-0193; 1563-5112
• DOI: 10.1080/00150193.2014.895217

Water exhibits unique physical and chemicals properties and its low frequency dielectric response is not an exception. The large directionable dipole moment of the water molecule results in a relatively high dielectric constant whose temperature dependence above 0°C follows well a Curie-Weiss law (ɛ s -ɛ ei ) −1 = (1/C)(T-T C ), with ɛ ei ≅ 6.6, C = 1.49 × 10 4 and T C = 90.4 K. The frequency dependence of the permittivity of pure water has recently been measured at various temperatures with high accuracy in the frequency range of 0 - 25 THz, showing a well-defined Debye-type relaxation behaviour, which can be described reasonably well by means of a paraelectric-like temperature dependence relaxation time given by τ −1 = υ D e −ϕ/k B T [(T-T C )/T], where υ D = 1.877 × 10 14 and ϕ = 0.180 eV. The combined pressure and temperature dependence of the dielectric constant is described approximately by means of a generalized Curie-Weiss state-law.