Dielectric and pyroelectric behaviour in (BPI)_x (BP)_1−x

Abstract

Measurements of dielectric constant, dielectric loss and pyroelectric coefficient as a function of temperature have been performed in mixed crystals of Betaine Phosphite (BPI) and Betaine Phosphate (BP) ((BPI)_x (BP)_1−x), for x = 0.80, 0.90, 0.94 and 0.97. The obtained results are compared with the ones previously reported for x = 0.00, 0.05, 0.15, 0.30, 0.60 and 1.00. Three regions are apparent: one where the ferroelectric properties are dominant (x > 0.90), another which can be related to a glassy phase (0.30< x <0.90) and a third one mainly associated with an antiferroelectric behaviour of BP (x < 0.30).