High‐Temperature Dielectric Constant of NaCl and KBr

A dispersion of the dielectric constant and associated dielectric loss has been observed in sodium chloride and potassium bromide at high temperatures and radio frequencies. Interpretation of the data in terms of the Debye theory of dipolar relaxation suggests that vacancy pairs are responsible for the phenomenon. The concentration of dipoles is, however, one or two orders of magnitude larger than the expected concentration of vacancy pairs.