有機溶媒の誘電性に関する研究(I)

Part 1. Dielectric Dispersion in Ultra Low Frequency (1)
Part 2. A New Equation on the Dielectric Constant of Binary Organic Solvent Mixtures

The dielectric dispersion in high frequency range have already been studied by P. Debye 1) , M. Gevers 2) , R. G. Brekenridge 3) W. Shotkley 4) and others 5). Debye had first introduced a theory that the dielectric constant in alternating field is generally expressed as a function of the frequency used, and is also expressed as a complex quantity owing to the presence of the internal friction between the dipole molecules in the alternating field, i. e
ε=ε'-jε" -------------------------------1)
where j^2 = -1, and
ε'=ε_<ea>+(ε_s-ε_<ea>)/(1+ω^2τ^2)----2)
ε"=ε_s-ε_<ea>(ωτ)/(1+ω^2τ^2)--------3)
In Eqs. 2 and 3, ε_s represents the dielectric constant in the static field and ε_<ea> is a dielectric constant due to atomic and electronic polarization, ω the angular velocity at frequency ν,τ the relaxation time. The real part of the dielectric constant ε" in Eq. 1 shows the ordinal dielectric constant due to the pure polarization, and this value decreases with increasing frequency. The second term, deduced from the lag of the phase angle, shows practically the dielectric loss due to the internal friction of the dipole molecules in the alternating field. By differenciating the both terms of Eq. 3, we can easilly deduce the following conclusion that the absolute value of the imaginary part of the complex dielectric constant has a maximum value when ωτ = 1. As clearly shown in Eq. 2, the real part of the dielectric constant decreases suddenly in the vicinity of the frequency at ωτ = 1. The above mentioned theory is actually proved in many organic dielectrics. Generally speaking, the fact that the dielectric constant observed in the alternating field varies with the frequency has been described in terms of dispersion.
In recent times, the studies of the dielectric properties of the various organic substances have been extended their trend of research not only to the analysis of the molecular stracture but also to their application for electrical technics. The dielectric loss angle which is expressed by the ratio of the two dielectric constants ε' and ε", has also been considered to be the most interesting subject on the electrical properties in solid state physics especially in high polymer substances.
In this paper, the dispersion of the dielectric constants in very low frequency below ten cycles per second has been investigated on the some organic substances such as dioxane or benzene.