Complex dielectric constants of Rochelle salt(RS)-ammonium Rochelle sa
lt(ARS) mixed crystal system have been investigated with a conventiona
l LCR-meter at temperatures from 20K to 295K at 10kHz. The obtained da
ta have been plotted on the epsilon'-epsilon '' plane, and they show a
fairly continuous locus. They show considerable difference among the
region I(0 < x < 0.025), the region II(0.025 < x < 0.18) and the regio
n III(0.18 < x < 0.92). The temperature where the epsilon '' is maximu
m is in the region of the ferroelectric phase in the region I and the
region III. In the region II, the maximum point of the epsilon '' is t
he higher temperature side than the temperature where the epsilon' is
maximum.