Ferro-Antiferroelectric Competitions in the (BP)_x(BA)_{1 − x} Mixed System

Abstract

We have attempted to understand the low temperature microscopic structure and dipolar ordering of the (BP)_x(BA)_{1 −x} mixed system in a previous work, by performing detailed pyroelectric, dielectric and polarization reversal measurements, complemented with Raman and infrared spectroscopic investigations. Whenever the same experimental techniques are used, our experimental results agree extremely well with those reported in the literature. However, our use of slightly different methods disclosed new aspects of the phase sequence, which allowed us to trace an alternative phase diagram for the (BP)_x(BA)_1−x mixed system.

The present paper is aimed at emphasising the most relevant of these previous results. Particular attention will be paid to the role of ferro-antiferroelectric competitions in the mixed system (BP)_x(BA)_{1 −x}.

Keywords:

• Disorder cooperative systems
• ferro-antiferroelectric competitions
• glassy phases
• non-ergodicity

Acknowledgments

This work was supported by “Programa FEDER/POCTI (Projecto no. 2-155/94 da Fundação para a Ciência e a Tecnologia)” and “Projecto POCTI/FIS/14287/2001 da Fundação para a Ciência e a Tecnologia”.