High Tc ferroelectricity in Ba-doped ZnO nanoparticles

• Signatures of ferroelectricity in Ba doped ZnO nanoparticles are reported first time (samples were not poled).
• Effects of Ba doping on structural, optical and ferroelectric properties of ZnO nanoparticles are presented.
• Studies of vibrational modes of nanostructures were examined by FTIR spectroscopy.
• High value of remnant polarization and low value of coercive field (in unpoled sample) were also observed in ferroelectric studies which can be useful for potential applications.

Effects of Ba doping on structural, optical and ferroelectric properties of ZnO nanoparticles prepared by a low cost thermal decomposition method are presented. The substitution of Ba on Zn sites of the wurtzite structure of ZnO was observed by X-ray diffraction. Some structural transformation in the morphology of nanostructure with Ba doping was observed. Redshift in band gap is observed in the UV–visible spectra after Ba doping, supported by photoluminescence spectra and showing enhanced defect states with Ba doping. In dielectric studies, high value of dielectric constant and transition temperature at (~330 °C) were observed. High value of remnant polarization (1.01 µC cm−2) and low value of coercive field (2.02 kV cm−1) were also observed in ferroelectric studies which can be useful for potential applications.