In search of an artificial morphotropic phase boundary: Lead free barium titanate based composites

Broadband dielectric spectroscopy was used to study potassium niobate (KN) and barium titanate (BT) core– shell-like composites. KN shell was obtained using a solvothermal reaction method. High frequency results show a huge anomaly that is associated with electro-mechanical coupling. We tried to extract spontaneous polarization values using a theoretical model. We also observed little or no evidence of KN-related phase transitions in the dielectric spectra, although infrared measurements showed typical KN spectral features. Furthermore, we show that a small change in the sintering process allows tuning of dielectric permittivity by an order of magnitude.