Preparation and ferroelectric properties of Ti-site substituted BaTiO3 thin films

Thin films of BaTi0.91(Hf-0.5, Zr-0.5)(0.09)O-3 on Pt/SiO2/Si(100), Nb-doped SrTiO3 (100) and (111) substrates were synthesized by a pulsed laser deposition method using fourth harmonic generated light of Nd3+:YAG laser beam under low O-2 partial pressure. The in-situ observation of BaTi0.91(Hf-0.5,Zr-0.5)(0.09)O-3 'film deposition on a Nb-doped SrTiO3 (100) substrate was performed using reflection high energy electron beam diffraction. The BaTi0.91(Hf-0.5, Zr-0.5)(0.09)O-3 films deposited on Nb-doped SrTiO3 (100) and (111)substrates showed preferential [100] and [111] orientations, respectively. The ferroelectric properties of BaTi0.91(Hf-0.5, Zr-0.5)(0.09) O-3 thin films were investigated by electrical measurements. The frequency dependence of the dielectric constant of BaTi0.91(Hf-0.5, Zr-0.5)(0.09) O-3 thin film was influenced by low dielectric phase, and it was analyzed by the Debye model. The remanent polarization and coercive field of BaTi0.91(Hf-0.5, Zr-0.5)(0.09)O-3 thin film were measured at room temperature, and those values were 7.4 muC/cm(2) and 123 kV/cm, respectively.