DIELECTRIC BEHAVIOR OF RS-ARS MIXED-CRYSTAL SYSTEM AT LOW-TEMPERATURES

Dielectric relaxation measurements on mixed crystals of Rochelle salt and ammonium Rochelle salt with 26% and 82% of ammonium salt concentra tion have been performed at frequencies between 1 kHz and 100 kHz in t he temperature range from 4.2 K to room temperature. Very broad relaxa tion processes have been observed and these strongly depend on tempera ture. It is suggested that dipolar freezing is observed and this dipol e is the same one which is responsible in the ferroelectric phase tran sition.