Ferroelectric behavior of TAAP single crystal near Tc

Dielectric and hysteresis loop measurements in good quality telluric acid ammonium phosphate from 20 to 50°C with special attention to the behavior in the vicinity of T_c ≈44.80 °C were performed. The effective field higher order parameters characterizing the temperature dependence of the spontaneous polarization were obtained. The main features of the ferroelectric transition in this “hard” ferroelectric have been compared with those of other well known ferroelectric crystals.