Dielectric spectroscopy of the room temperature molten salt ethylammonium nitrate

The complex permittivity of ethylammonium nitrate has been measured as a function of frequency between 3 MHz and 40 GHz at eight temperatures between 288.15 and 353.15 K. The spectra are well represented by a sum of a conductivity term and a relaxation spectral function that reflects an unsymmetrical relaxation time distribution. Parameter values are given for the Cole-Davidson term and the Kohlrausch-Williams-Watts model. Molecular mechanisms in conformance with an unsymmetrical relaxation time distribution are discussed. The dominant relaxation process with a relaxation frequency in the accessible range can be explained by the formation of a small amount of dipolar ion complexes. The values for the extrapolated high-frequency permittivity indicate a further relaxation process, well above the frequency range of measurements, which is likely to reflect modes of motions of the cation and anion lattices relative to one another.