This study presents a comparison between the inclusion-type and layer-type ceramiceceramic composites,
consisting of relaxor and piezoelectric phases, in terms of polarization and strain behaviors.
Bi(NaK)TiO3 (BNKT) and 0.94Bi(NaK)TiO3e0.06BiAlO3 (BNKTeBA) 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/BNKTeBA, 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.