The dispersion and absorption of a considerable number of liquid and dielectrics are represented by the empirical formula In this equation, ε* is the complex dielectric constant, ε0 and ε∞ are the ``static'' and ``infinite frequency'' dielectric constants, ω=2π times the frequency, and τ0 is a generalized relaxation time. The parameter α can assume values between 0 and 1, the former value giving the result of Debye for polar dielectrics. The expression (1) requires that the locus of the dielectric constant in the complex plane be a circular arc with end points on the axis of reals and center below this axis.
If a distribution of relaxation times is assumed to account for Eq. (1), it is possible to calculate the necessary distribution function by the method of Fuoss and Kirkwood. It is, however, difficult to understand the physical significance of this formal result.
If a dielectric satisfying Eq. (1) is represented by a three‐element electrical circuit, the mechanism responsible for the dispersion is equivalent to a complex impedance with a phase angle which is independent of the frequency. On this basis, the mechanism of interaction has the striking property that energy is conserved or ``stored'' in addition to being dissipated and that the ratio of the average energy stored to the energy dissipated per cycle is independent of the frequency.
REFERENCES
1.
P. Debye, Polar Molecules (Chemical Catalogue Company, New York, 1929).
2.
Reference 1, p. 94.
3.
This constant is not the same as the relaxation time as defined by Debye, differing from it by a constant factor which depends on the theory assumed for the static dielectric constant, cf.
R. H.
Cole
, J. Chem. Phys.
6
, 385
(1938
). The distinction is unimportant for the present discussion.4.
J. C. Maxwell, Electricity and Magnetism (Oxford Press, London, 1892), Vol. I.
5.
6.
7.
8.
9.
“Dispersion and absorption in dielectrics. II. Direct current characteristics,” to be submitted to this journal.
10.
See, for example,
K. S.
Cole
, J. Gen. Physiol.
12
, 29
(1928
);K. S.
Cole
, J. Gen. Physiol.
15
, 641
(1932
)., J. Gen. Physiol.
11.
This procedure is not without uncertainty because of the possibility of atomic polarization giving rise to absorption in the infra‐red and a related dispersion of which this extrapolation takes no account. In the absence of definite information on this point, one can do no better than to ignore the difficulty. The error should not, in most cases, be serious.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
A. H.
White
, S. S.
Biggs
, and S. O.
Morgan
, J. Am. Chem. Soc.
62
, 16
(1940
).23.
24.
The sources of the data are: chlorinated diphenyl, reference 16; glycol phthalate resin,
W. A.
Yager
, Physics
7
, 434
(1936
);Halowax, reference 15;
25.
26.
H. A. Kramers, Atti Congr. dei Fisici, Como, 545, 1927. See also reference 6.
27.
28.
29.
It should be emphasized that this “absorption conductivity” refers only to the conductivity associated with dispersion. It does not include any “direct current” steady‐state conductivity as will be discussed in a later paper (reference 6).
30.
31.
32.
33.
L.
Hartshorn
, N. J. L.
Megson
, and E.
Rushton
, Proc. Phys. Soc.
52
, 796
(1940
).34.
A. H.
Scott
, A. T.
McPherson
, and H. L.
Curtis
, Bur. Stand. J. Research
11
, 173
(1933
).35.
See, however, reference 10.
36.
37.
38.
See, for instance,
J. H.
Van Vleck
, J. Chem. Phys.
5
, 556
(1937
), and reference 3.39.
40.
41.
42.
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