The dielectric constant ε
and the electrical conductivity σ were
measured of crystalline plates cut
perpendicular to the a-, b-, and
c-axes from K2ZnCl4 (KZC)
crystals, pure and doped with Co2+ ions, in
the temperature range from 300 to 500 K. A pronounced broad
peaks exists at the commensurate-incommensurate phase transition
temperature (Tc1).
A thermal hysteresis of about 10 K is observed for
the transition during heating
and cooling processes. The J-E
characteristics along the crystallographic axes were measured below
and above Tc1. Conductivity
anomalies were observed at Tc1. The
results of electrical conductivity temperature measurements were
analyzed and the activation energies of conduction at different
temperature regions have been evaluated. The mechanism of the
electrical conduction of the various phases and the anomaly at the
transition point was discussed.