Enhanced ferroelectricity in NaNbO3-LaCoO3:Mn epitaxial thin film

A (001)-oriented NaNbO3-LaCoO3:Mn thin film with enhanced ferroelectric properties was successfully deposited on a SrRuO3-buffered LaAlO3 substrate by radiofrequency magnetron sputtering. This epitaxial thin film modified by element doping shows a tetragonal ferroelectric structure and large remanent polarization (31 mu C cm(-2)) with high Curie temperature (450 degrees C). The polarization fatigue tests demonstrate an improved fatigue resistance due to the reduced oxygen vacancies by element doping. Further X-ray absorption spectra experiments found that the split energy between Nb t(2g) and e(g) orbitals is reduced and the hybridization between transition metal d-O 2p is strengthened, leading to enhanced ferroelectric polarization.