Enhanced piezoelectric response of BaTiO 3 -KNbO 3 composites

The piezoelectric response of solvothermally synthesized BaTiO 3 (BT)-KNbO 3 (KN) composites (the nominal BT/KN ratio was 1) with distinct interfaces was investigated. The x-ray diffraction pattern showed two distinct peaks began to merge into a singular broad peak at a two-theta position between (200) and (002) tetragonal-related peaks of BT. The transmission electron microscopy observation showed a heteroepitaxial interface region between BT single-crystal particles and deposited KN crystals. The large-field piezoelectric constant was 136pC/N, which was three times larger than that of a sintered 0.5BT-0.5KN composite. The enhanced piezoelectric response was attributed to the strained epitaxial interface region.