Solvothermal growth of BaTiO₃ thin films on Ti foils at T ≤ 200 °C with ferroelectric behavior

Abstract

Polycrystalline BaTiO₃ thin films were grown solvothermaly on titanium foil by introducing barium hydroxide solution in a Teflon line and allowed to react with the foil during the autoclave process. Different molar concentration of Ba(OH)₂ were investigated: 0.5, 1 and 2 mol·L⁻¹ with three heating temperatures: 150, 175 and 200 °C. The films were characterized by XRD and revealed characteristic peaks of BTO with a slight preferential orientation along the [00l] directions. The SEM characterizations showed dense thin films with spherical grains. The relative permittivity is about 400 and dielectric losses below 0.05 in the frequency range 10² to 10⁷ Hz.

KEYWORDS:

• BaTiO₃ thin films
• solvothermal synthesis
• low temperature
• high dielectric constant εr
• low loss factor tanδ

Acknowledgments

We thank N. Stephant, Service commun de microscopies, Faculté des Sciences, Nantes for help at SEM studies, P.-E.Petit for XRD studies. We also thank P. Derval for help in electrode deposition.