Comparative study of the polarization and strain of inclusion-type and layer-type 0.94Bi(NaK)TiO3-0.06BiAlO(3)/Bi(NaK)TiO3 ceramic composites

摘要

This study presents a comparison between the inclusion-type and layer-type ceramic-ceramic composites, consisting of relaxor and piezoelectric phases, in terms of polarization and strain behaviors. Bi(NaK)TiO3 (BNKT) and 0.94Bi(NaK)TiO3-0.06BiAlO(3) (BNKT-BA) were prepared for ferroelectric and relaxor materials, respectively. In the case of the layer-type composite, the polarization and strain behaviors were observed as a function of the volume ratio of the relaxor/piezoelectric phases. With an increase in the ratio of BNKT/BNKT-BA, a larger strain was obtained with the electric field. For the inclusion-type composite, the largest saturation polarization with double hysteresis loop and large saturation strain were measured at a ratio of 0.2. Comparison of the two composites indicates that larger polarization and strain were observed for the inclusion-type composite than the layer-type composite. This may be related to the fact that the ferroelectric phase serves as a preferential nucleation/growth site for the relaxor-to-ferroelectric phase transition in the relaxor matrix, which was evaluated using the polarization dynamics of the ferroelectric materials. (C) 2015 Elsevier B.V. All rights reserved.