Effect of Li doping on ferroelectric and piezoelectric properties of Ba0.5Na0.5TiO3-BaTiO3 (BNT-BT) thin films

Abstract

The piezoelectric and the ferroelectric properties of x-mol% Li-doped 0.94Bi0.5Na0.5TiO3-0.06BaTiO3 (BNT-BT-Lix), x = 0, 5, 10, 15, 20) lead-free piezoelectric thin films deposited on Pt (111)/Ti/SiO2/Si substrates via a metal-organic solution deposition method were investigated. Our results show that the Li-substituted film has a remarkable improvement in electrical properties compared with the BNT-BT film. We also found that the substitution was effective in decreasing the coercive field in the thin films. The enhanced electromechanical properties are contributed by both crystal structure evolution and improved microstructure. The optimal ferroelectric properties were obtained in the film with x = 10 providing a remanent polarization (Pr) and a coercive field (Ec) of ~23.9 μC/cm2 and ~124 kV/cm, respectively. © 2013 The Korean Physical Society.