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Complex perovskite Ba(Fe1/2Nb1/2)O3 thin films are grown on Pt/TiO2/SiO2/Si substrates by pulsed laser deposition.Non-linear polarization-electric-field (P-E) loops are observed at low temperatures under different electric fields and frequencies.The broad peak in the corresponding current density electric field (J-E) loop confirms the existence of domain switching.The remnant polarization decreases slightly when the temperature decreases from 153 to 123K,which differentiates Ba(Fe1/2Nb1/2)O3 from normal ferroelectrics.The Raman spectra of Ba(Fe1/2Nb1/2)O3 thin films show two-mode-like behavior in the high-wavenumber region,which can be caused by the local chemically heterogeneous zones of NbO6 and FeO6.The weak ferroelectricity observed in the Ba(Fe1/2Nb1/2)O3 thin films might originate from the composition fluctuation and subsequent symmetry brealdng in the material.The present results might provide a new aspect to the understanding of the intrinsic dielectric nature in Ba(Fe1 / 2 Nb1 / 2) O3.